Dealing with calcification

Last issue we covered the affliction of corrosion, but boats that remain in the water for long periods suffer from the reverse problem – calcification. Or, more completely, the dual issues of biological growth and calcification. This is where the boat gets more mineral and biological material added to it, rather than having it corrode away.

This affects all surfaces, not just metal ones, and of course this encrustation is the reason we apply anti-fouling paint to the underside of the hull. Unfortunately, the most effective biocides are no longer available to us because they were polluting our waterways while protecting our hulls. So, these days we are often playing catch-up, slowing rather than preventing the growth of biological material.

The difference between the damage caused by acid, compared to Rydlyme, bottom. The top group is untreated, the middle group was soaked in Rydlyme and the bottom group in Descaler. The brass has started the turn back to copper as the zinc is dissolved.

Calcification is slightly different – it’s actually the deposition of the mineral calcium carbonate onto surfaces. This happens particularly in areas where sea water is heated, which accelerates the deposition of this naturally-occurring mineral. Heat exchanger tubes are the worst location for this type of deposition, but it can occur where sea water remains in contact with any surface without vigorous movement.

Many forms of encrusting marine growth will also cause some calcification – think of oyster shells, barnacles and coralline algae, that hard, red-coloured coating that covers rocks underwater. These can coat boats as tenaciously as pure mineral deposits, requiring the same effort to remove.

Apart from the obvious surfaces on your boat, most boaties will at some point come across calcified items that have been dropped into the sea and stayed submerged for some time. Fishing rods, anchors, ropes, nets, scuba gear, cameras and other ‘treasures’ regularly suffer this fate. It’s surprising how quickly these become encrusted. Small barnacles are usually in the vanguard, but other hard deposits soon follow.

Removing these calcified deposits is theoretically a simple matter since calcium carbonate dissolves quite readily in acid. Drop any seashell in even a mild acid solution such as vinegar (acetic acid) for a time and very soon bubbles appear all over the solution’s surface. Leave it submerged long enough and eventually the shell will dissolve completely.

So, flushing an item in a suitable acidic solution will soften the calcium carbonate so that the encrustation either drops off or completely dissolves. The danger with this approach is that acid damages many things, including the metals we commonly use on our boats.

That shackle after two hours in Rydlyme. Rust and barnacles completely gone.

The behaviour of different acids on different metals is a subject to itself. There is no simple acid that works and is safe for all our common materials. Hydrochloric acid, for example, is a common cleaning solution for concrete and pickling steel. However, it will attack virtually every metal found in a boat, including the engine, scuba gear and fishing tackle.

We pulled out a table of the common metals and the readily available acids as shown on the previous page.

So, how do we clean out calcification? Using a plain acid, even highly diluted with water, is not a good option. Unfortunately, most industrial and domestic products such as Acid Descaler and CLR are simply combinations of acids. These are both available through hardware stores.

The candidates for treatment.

Luckily, there are some products out there specifically for boaties that mitigate some of the risks, combining a low-level of acidity with some biocides and other ingredients. Rydlyme, distributed by Auckland Marine Services, and Barnacle Buster from Trac Ecological, distributed by Ovlov Marine, are two readily available examples. Both of these products are biodegradable non-toxic marine growth removers that are simply re-circulated through the saltwater cooling system. No need to disassemble the engine – and depending on how your cooling system is plumbed – using them may require just a couple of hose connections.

To compare the effectiveness of the products, we ran a number of tests. Firstly we took some sample items (two brass screws and a brass fitting), and soaked them for an equal time (30 minutes) in Rydlyme (middle group) and Acid Descaler (at the bottom). The photo shows how quickly the brass started to de-zinc in the acid solution, turning back into a spongy copper rather than hard brass. Also of note: the chrome-plated hose fitting subjected to this treatment lost its chrome plating. The middle group in the photo shows the Rydlyme had no damaging effect on the brass, apart from a very slight surface discolouration.

We also fortuitously happened to have some items salvaged after a long period on the sea bottom. These included a stainless steel and a high-tensile steel shackle, some scuba gear and some cheap nickel-plated snap shackles.

These objects were soaked in a diluted Rydlyme solution for two hours, then rinsed off. As can be seen, the steel items came up perfectly. The scuba items were also clean and usable once again, with some discolouration of the chrome plating being the only lasting impact. Only the cheap nickel plating showed extreme discolouration, but the items were fully functional after the clean.

For comparison I’d previously attempted a similar clean of another regulator using Acid Descaler, which destroyed the components – the brass elements de-zinced so badly the threads crumbled, and the regulator literally fell apart when it was subjected to air pressure.

So, the outcome of all this experimentation is clear – don’t be tempted to use an acid solution to descale or clean your engine. Instead, pay the money and buy one of the certified, biodegradable, marine-friendly products. Follow the manufacturer’s instructions regarding dilution and soak time and you should have no problems. BNZ

After treatment: completely useable again. Note some discolouration of the chrome plating does occur.



The process of running a suitable (and safe) de-scaling product through your engine is relatively simple:

1. Remove all zinc anodes from inside the engine. These are typically inside the heat exchanger but there may be others. When you remove the anode, replace the plug to prevent water leaking out the hole.

2. Block the saltwater intake through the hull by closing a stop cock.

3. Connect a circulating pump that can feed water into the engine’s saltwater circuit via the engine intake side. In my case the main intake hose had a smaller connection that the washdown pump was connected to. I simply plugged into this. At worst you may need to disconnect the main inlet hose and plumb into that.

4. Undo the saltwater outlet hose (which may feed into the exhaust, or through its own through-hull fitting above the waterline), and feed this into a large bucket or similar container.

5. The circulating pump should be set to suck water from that bucket and pump it into the inlet hose. 6. First fill the bucket with freshwater and flush the system. Repeat to make sure you have eliminated all the saltwater. Note you may need to start the engine if your saltwater pump is part of this circuit.

7. Then replace the freshwater with the descaling solution, and leave circulating for two to four hours, according to the manufacturer’s recommendations. I prefer not to leave my engine running without cooling water running into the exhaust, so I started and ran it for 30 seconds once every five minutes. This refreshes the de-scaler solution that is sitting in the heat exchangers and pipes.

8. Once the process is complete, remove the descaler solution and flush the system again with freshwater.

9. Remove the extra plumbing, replace the anodes with a fresh set, and re-open the stopcocks.

10. Job done. Your engine should now run cooler and more efficiently.

Rust never sleeps

According to the musician Neil Young, “Rust Never Sleeps”. Young must have been a boat owner, because certainly rust, or more generically corrosion, never stops trying to eat away at any metallic object on your boat that’s in contact with salt water.

It does this relentlessly, 24 hours a day and 365 days a year. And the process is not linear – something can look good and solid for a long period of time, and then very quickly deteriorate, developing pits and holes before starting to lose strength and eventually crumbling away.

About six months ago my fibreglass-hulled launch was hauled out for an overnight job – fitting a new transducer for the fishfinder. At the same time, we gave the hull a quick clean and checked her over. The antifoul was holding up well, just over halfway through its effective life, although the props had lost some of their protective coating. Since it was only a quick haul out, we could not re-coat the props, but they still looked solid so we expected no problems.

A typical prop nut anode

Fast-forward four months, and at the end of a crayfish dive I did my usual maintenance check of the boat’s running gear before I climbed back on board. I was horrified to find two small holes had appeared in one propeller, going right through the blades on the starboard side. The leading edges of the blades were also badly pitted and thin as tinfoil in places. Something was eating the bronze! The port side propeller, on the other hand, looked fine, with no corrosion whatsoever.

Pulling an 11m launch out the water is not a trivial process, and since we had just come out of lockdown there was a long backlog for haul outs at the marina. So, first thing was to try and identify what was causing the corrosion on the bronze propellor – and more importantly, limiting any further damage until I could pull the props off for repair.

As every boat owner knows, anodes are the ‘big guns’ when it comes to protecting against corrosion. These are usually zinc, although sometimes aluminium, and they are sacrificial metal blocks that are kept in electrical contact with every metal component on the hull. Then when saltwater sets up the inevitable galvanic process, the item that starts to corrode away first is the anode. Once it wears down you replace just that one component, saving all other metal items.


I knew my boat still had good anodes, since that is one of the items I checked during my dive. I re-checked all my electrical bonding straps, which connect the engine, drives etc to the hull and anodes. All of them seemed good, with nothing obviously loose. Time for an expert opinion. I made a call to Half Moon Bay Electrical and booked an urgent galvanic protection survey.

The process is, conceptually, quite simple. An electrical meter is used, with one probe in the water next to the boat and the other used to make electrical contact with various components of the boat. The meter measures whether current is flowing between the item and the surrounding sea, how well they are bonded together and how effectively the anode is working. The test showed all was within expected parameters, with one exception – the starboard drive shaft and propeller assembly had no electrical connection to the rest of the boat.

That drive shaft is connected to the engine through a flexible coupling, essentially a big plastic polymer ring that prevents engine vibration being transmitted to the drive. This means that there is an electrically insulating rubber surface between the metal of the gearbox and the driveshaft. Similarly, the shaft runs out of the boat through a cutlass bearing, again made from a plastic polymer material that prevents the shaft from making electrical contact with the stern tube.

A typical prop shaft anode

Quite commonly in this configuration there would be a twopiece zinc anode bolted tightly around the shaft in the water end of the assembly. However, on my vessel there is less than 10mm of shaft between the tube and propellor.

Another common protection is to have an anode that attaches directly to the prop nut, but again, my launch has no provision for this. This configuration has been unchanged for the seven years I have owned her and this issue has not arisen before.

Discussing the issue with Simon Jennings from HMB Electrical, he advised that a two-pronged approach was best. First was to get some form of electrical protection onto the shaft. The second was using a prop coating like Prop Speed or a similar product. It would physically protect the surface of the bronze.

Normally my props are well coated, and as mentioned, I have not had this issue before. But on my dive, I noticed that the starboard side had lost a good part of its coating, possibly due to poor application. And now I have this big problem.

By articulating the brush, gravity can provide the necessary wipe force on the shaft


Graphite brush soldered to the copper – not neat but solid!

Removing the props, repairing the damaged area, rebalancing them and then finally re-coating both props will happen when I can get her hauled out the water.

In the meantime, the only option for electrical protection is what is called a bonding shaft brush. Because the shaft is spinning, any electrical connection needs to make contact with a rotating surface. Electric motors do this all the time, with graphite brushes that make an electrical connection to the rotor contacts. The graphite conforms to the shape of the shaft and then provides continuous connection through a copper wire. The graphite slowly wears down over time, but since they are not metallic at least brushes do not corrode.

Unfortunately, although BEP Marine makes a generic model bonding shaft brush, I was unable to find a local supplier with any in stock. That would mean an overseas purchase, shipping costs and delays. Looking at the detailed pictures of their product, I realised it would be relatively simple to make, requiring just a strip of solid copper and suitable-sized starter motor brushes.

Finished installation.

Both of which turned out to be quite easy to source. Copper strip is readily available from industrial electrical suppliers where it is used for busbars. Again, supply issues limited what I could get, but a piece of 6mm x 19mm copper would do. Ideally, a thinner strip would have been better. I also had to buy 1.5m, so I now have plenty of spare copper for future projects!

Starter motor brushes are easily obtained from automotive stores, but I bought the biggest and cheapest version I could find on TradeMe to go with the sturdy double copper wire for soldering. For $20 I got a set of four brushes, and these proved to be exactly the right size (20mm wide and 9mm thick) for my copper strip.

Making the unit was a simple job of cutting a 50cm strip of copper, notching the end for the copper braid to fit through, then soldering the wire to the strip. This was well beyond the capacity of a soldering iron, so a small blowtorch was used to heat up the copper enough to melt the solder. And finally, I neatened up the edges and drilled some bolt holes for mounting.

Access was difficult

At this point I realised a small modification was needed. The graphite part of the brush needs to stay in continuous contact with the shaft, which means it needs to be under a small amount of pressure to allow for movement. Not too much, however, or it would wear away very quickly. Either a small spring or gravity was needed to maintain that pressure. I considered whether the natural springiness of the copper would be sufficient but decided this was too unpredictable.

Instead, I cut right through the copper strip about a third of the way along and soldered a short length of copper braid across the gap. This created an articulated joint that would allow the weight of the brush end to maintain the required contact. I scrounged the braid from a spare welding earth clamp I had at home.

The orange plastic coupling is an electrical insulator.

Installing the brushes was theoretically simple since I just had to drill two holes in the engine mounting frame and bolt it in place. But, of course, securing it was a contortionist’s nightmare, taking much swearing and sweating. Eventually the job was done, as can be seen from the pictures.

Time will tell how effective this will be, and I am not sure whether I should have painted the raw copper to prevent it also corroding? When I haul the props off in a few weeks’ time I will review the installation and make any changes needed.

Total cost was around $120, but now I have enough copper bar and two spare brushes to make another complete set. Anybody else need one? BNZ

This is how a propeller should be protected – with a thorough coating of Propspeed.

Fitting a steering indicator

One of the useful, but not necessarily essential, gauges on the helm of a boat is an indicator showing which way the rudder is pointing.

This is of course more important on a yacht with an underslung rudder, or a launch where either the rudder or sternlegs are not visible from the helm position. Without some sort of direction indicator, you have no idea which way the boat will steer when you apply power. This could have disastrous consequences if the boat suddenly moves the wrong way.

Such an indicator is usually not required on boats powered by an outboard motor, since a quick glance backwards at the powerhead will indicate which direction it is pointing. However, if the helm position is located too far forward, if the skipper is steering from a flybridge, or even if the cockpit has an overly high transom wall, then the outboard may not be easily visible from the helm station. Another issue is a skipper with restricted neck mobility, who may find it hard to repeatedly swivel his head through 180° while manoeuvring.

A steering indicator on the dashboard may be a good option in these cases as well.

My friend struggled to see which way his outboard engine’s thrust was directing from the helm, so we decided on a steering indicator at the helm.

Conventional solutions have a direction sensor with an arm that is attached to the rudder. As that arm pivots a variable resistor inside the base of the unit detects the angle of the rudder and displays the position on the dash gauge. Inboard propulsion systems such as a waterjet or an IPS pod will have a similar mechanism, although it will most likely be swung by a steering rod instead of the rudder. In both cases, however, the relatively fragile mechanism is usually hidden behind a bulkhead or below decks where there is space for things to move around freely without risk of snagging.

It is not so simple on an outboard-powered vessel. The motor generally sits in an open well or on the transom, and there is usually very limited space around it for things to swing around. Worse, the entire outboard tilts up, so any mechanism needs to be able to move up and down with the motor. And lastly, because of their position, you cannot install a flimsy rod and swivel arm that will get snagged up on gear, stub toes etc. Hence a conventional direction sensor is generally not a viable solution.

The sender is relatively simple, with a collar that slides along the tube. The IP68 fully immersible connector, bottom, is necesary for a join in the wiring that sits out on the boarding platform.

The solution is a sealed, tube-style sender, similar to the sender unit we fitted to our water tank a few months ago. This is a slim design that is clamped to the outside of the steering cylinder. It then has a moving magnetic collar, clamped to the steering ram, that slides over the sealed tube as the outboard moves. The magnet operates a series of reed switches inside the sealed tube, which detect the position and translate that into the direction that the motor is pointing. These units are made by KUS, and although the outboard steering indicator model is not readily available in New Zealand, it can be ordered through most outlets that sell other KUS units.

The installation of the sender unit is fairly simple: a fixed clamp goes around the steering cylinder and holds the tube, and a sliding magnet is clamped to the end of the steering arm. Suitable clamps are provided for both, but it takes a bit of headscratching to work out the best position that won’t impede the steering action and will also not be in the way when the motor is fully tilted up.

The tube clamps onto the hydraulic cylinder, and the collar clamps onto the steering extension.

In our case the steering rod itself was almost flush with the end of the cylinder at either end when the steering was at full lock, so we had no place to clamp the magnetic collar. There were a couple of ways we could have solved this but the simplest seemed to be to make a short extension to the steering ram. A piece of stainless tube with the same diameter as the rod was sourced, and a 10mm slot cut into it. A bit of judicious grinding ensued, and to fit it we unscrewed the steering arm and replaced the two existing washers with the extension tube. As can be seen from the photos, the end result is a tidy solution that looks like it was part of the original steering.

After fitting the clamps, we tried a few tilt-and-trim motions of the motor to ensure nothing was jamming. This resulted in a few slight changes to the position of the unit, after which we securely tightened up the clamps. The last part of this job was to cut off the extra bolt length and ensure there were no sharp edges for unwary feet to find when standing on the boarding platform.

Tilt the motor up and down a couple of times to check everything swings without jamming or catching anything.

The second part of the job involved the electrical connections up to the gauge on the helm. The only frustrating part of the kit was that the tail end of wire on the sender was far too short to reach across the boarding platform into the relatively dry area inside the cockpit. This meant a join in the wire was required, outside on the boarding platform where it will regularly get soaking wet. We needed a solution which was not just waterproof but fully immersible. The meant an IP68 connector, rated fully waterproof for up to 30 minutes at 1.5m of depth. Back to the chandlers!

It is important when planning a watertight connection that the gland on the connector correctly matches the cable. Unfortunately, current global supply chain issues mean that the most readily available twin-core marine cable is flat, but the Amphenol branded IP68 waterproof connectors that are available are only suitable for round cable of between 6 and 8mm in diameter. It took a bit of scurrying around to source marine-grade cable of the right diameter, after which the actual connection was a simple process.

We definitely do not want any clutter on the boarding platform.

In our boat there was an existing conduit that we could use to pass the cable up through the transom, by threading it down the same tube as the outboard control cables. If this was not available, then a further watertight joint would have been required to safely allow the cable to pass through the transom without allowing any water ingress. Products such as the Scanstrut Deck Seal could have been used to provide a fully waterproof seal. We did not require it since we were able to feed enough cable through the outboard cable duct to reach the helm.

Having sorted out the wiring path, the second half of the installation took about an hour. This included fitting the IP68

connector, feeding the cable through the wiring duct from the transom up to the helm, cutting a suitable hole in the dash and fitting the gauge, and then connecting it all up. A quick test showed everything was working.

The gauge snugly fitted into the dash.

Now for the proof of the pudding. I had installed this on my buddy’s boat since he has challenges whenever he manoeuvres his boat around the marina. His boat is not particularly responsive to the steering, and he sometimes turns the motor the wrong way when he is looking behind him. However, with the new indicator he can simply keep his head facing forward, either looking at the marina ahead or at the helm. The indicator will tell him which way the stern will travel when he puts the motor into gear, so he should find it a lot easier to move her in and out of her berth.

Just as I was finishing the job, my OCD tendencies kicked in and told me the overall layout of the dash was now a mess. Time to make a new helm faceplate and reposition everything. But that is another project for another day… BNZ

Unfortunately there was no space to fit the sender when the steering was at full lock.

Fitting a gauge to your water tank

Take the guesswork out of estimating how much water your boat is carrying.

Most boats with an underfloor fuel tank will have a fuel gauge. Which is a good thing, given how critical it is to know how much fuel you have on board. However, the same cannot be said for water tanks. Many launches and yachts have these tanks fitted but there is often no indication of the current fluid level. Fortunately, unless you are an offshore cruising vessel, running out of water is usually just an annoyance. Conversely, having a full holding tank is easily dealt with by taking the appropriate action, depending on where you are located.

Nevertheless, it is useful to have some way to know at a glance how much water you have in a particular tank. In my launch the freshwater tank holds about 150 litres, and because of the associated weight I prefer to keep this tank only half-full unless I am heading out for an extended trip. This means that most of the time I have no idea exactly how much water is in the tank, since I seldom fill it up to the brim. The tank is hidden under the saloon step where it is not readily accessible, so I can’t even tap on the side of the tank to estimate the level. Fitting a gauge was a long-overdue improvement I finally decided to tackle.

The final layout, with the water gauge fitted.

The most important part of the installation is getting the right sender, which is the part that goes into the tank to sense the fluid level. Most fuel senders are variations of a standard design and come in one size, with a multi-way adjustable float arm that can be set to suit the tank depth. However, these are generally NOT compatible with water tanks, because they contain two or three different types of metal and that old foe, corrosion, would soon attack the connections. For any system containing water you need either a fully-sealed magnetic tube sender or a noncontact ultrasonic type system.

Ultrasonic sensors work much like a fishfinder’s transducer, bouncing a sound wave down and measuring the ‘echo’ off the surface of the liquid. They have the advantage that they have no moving parts and do not even normally come into contact with the water. The downside is that these sender units are quite bulky and protrude above the top of the tank. In my case we have only about 15mm gap between the tank and the saloon floor panel.

Reed tube sender on the left, a conventional float sensor on the right; The water tank is under here!

Hence, I opted for a reed tube sender, made by KUS and available from most marine chandlers. Inside the sealed stainless tube is a line of small reed switches, and a floating magnetic collar around the tube turns the switches on and off as it moves up and down. The top of this unit only sticks about 10mm above the tank and would be clear of the floor panel above it. The downside of this type of sender is that they are non-adjustable and thus you must install the correct length unit to suit the dimensions of your tank. We matched the sender with a KUS water level gauge, again available from most chandlers with a choice of black or white bezel.

The job initially looked like it would be easy, but like many such projects it proved to have a few challenges. Accessing the tank was the first issue, which required removing the saloon table and carpet, then dismantling the cupboard door and surrounding trim. Once this was out the way I could lift and remove the large aluminium floor panel to gain access to the water tank.

Cutting the hole in the top of the tank.

Disappointingly, this had no provision made for a sender. Many manufacturers pre-cut the standard sized hole and fit a blanking plate over it, but this looked to be a custom-made tank. Hence cutting a suitable hole into the tank was required. Since this is a water tank it was safe to do while still in the boat – see the sidebar above on working with fuel tanks. After draining the water from the tank, to make it easier to clean the metal shavings afterwards, I used a metal hole saw to cut the correct-sized opening.

This was my first snag – all tanks have vertical strips called baffles, to stop their contents sloshing around. There was no obvious indication on the top of the tank as to where these were, and by sheer bad luck my first hole was directly over a baffle. Grr! So, I had to cut a second hole clear of the baffles, and fit a sealed blanking plate over this first one.

The first hole. Dang it! There’s a baffle right there!

One other advantage of the reed tube sender is that the direction the unit is facing does not matter. The floating-arm type of sender used in fuel tanks requires sufficient clear space inside the tank for the float arm to move up and down, hence it must be angled clear of any of those internal baffles or the sides of the tank. The reed tube has no such issues, but it also pays to know that the five screws around the top of the sender are not symmetric – the unit can be screwed in one position only, based on the pattern of screw holes that were drilled.

After cleaning the metal shavings from the tank, and using the opportunity to also remove some old gunge from the bottom of the tank, I fitted the sender using the supplied rubber gasket and screws. A length of two-core tinned cable was connected and fed back up into the wiring channel in the boat. Lastly, the cabin could be reconstructed – the floor plate refitted, cupboard surround and door reinstalled, and the saloon table returned to its mounting pedestal.

The sender fitted and wired with the cable attached.

At this point the next issue became apparent. Well, not really an issue but something of a pain. The tank is located on the port side, and the helm is on the starboard side. Because the boat is a catamaran and there is no mid-cabin channel connecting the hulls, I had to feed the cable all the way to the bow, then across the width of the boat through the wiring channel there, then back through the channel on the starboard side and finally up into the helm. This took over an hour of fiddling and feeding wires through tight spaces.

Fitting the gauge itself to the helm was easy enough, and after checking clearance at the back I simply used the hole saw to cut a suitable opening near the other gauges. Apart from the two wires from the sender, the gauge needs a 12v supply and then an optional, separate switched supply for the backlight. It was easy enough to just daisy-chain these off the matching wires on the other gauges, and a quick test showed everything seemed to be working as required.

Installed and ready for calibration. I found there were still about 20 litres remaining in the tank when the gauge showed empty.

After cleaning up, the last step is getting an understanding of the approximate gauge calibration. I filled the tank up in increments of 20 litres. Because the tank is 170mm deep and the closest reed tube length available was 150mm, the gauge only started to register a water level once I had added about 20 litres. After 60 litres it was showing just under half full, which for my purposes is the optimum level for a day trip. I continued to fill it up to confirm the readings when ¾ full and also when completely full, then drained about half the tank out again. Now I know that when it gets close to empty I have 20 litres or less and should put some more water in before my next trip out.

Job done. Total time was about 5 hours, thanks to the complexity of accessing the tank through the floor and then feeding the cable all the way around to the helm. The sender cost $69.99, the gauge was $79.99 and I used about $20 of marine-grade twin-core cable. Total cost just under $170. I considered fitting a similar gauge to my holding tank, but decided it was not worth the effort and cost at the moment. Perhaps a future project? BNZ

Using a hole saw to cut the hole in the wooden fascia for the gauge.


Note that cutting or drilling into any sort of fuel tank is extremely hazardous. Even diesel fuel can ignite, and the spark from a drill or hole saw can be enough to trigger an explosion in petrol tanks. Without specialist gear there is only one safe way to do this: Empty all the fuel out, then completely fill the tank with water right up to the overflow tube. You must ensure there are no air bubbles, potentially containing fuel vapour, anywhere in the tank.

Obviously, this is more easily done if you can remove the tank from the boat. Another recommendation is to use a battery-powered drill, to reduce the risk of an electrical shock once the bit gets through and starts spraying water around. Once the main hole and correctly-spaced screw holes are cut and tapped for the securing bolts you can then use a file to remove burrs or sharp edges. Then, and only then, can you drain the water completely out and dry the inside of the tank off before reinstalling into the vessel.

Working with plastic

Historically boats were built of wood, although various forms of metal (iron, steel then aluminium) became more common during the industrial revolution. The invention of fibreglass and epoxy resins in the 1930s added an exciting new material to the mix, and most boats are still built from one or more of these materials. They are easy to work with, well proven and cost effective.

More recently the concept of completely plastic boats developed, most commonly using rotationally-moulded polyethylene. This material is durable and lightweight, almost indestructible and requires no painting or finishing. As the technology matured it became possible to make bigger and bigger items, with boats over 10m long having been made in Australia. Currently the Mac 700GY (at 7m LOA) is the largest plastic boat produced in New Zealand.

The problem hatch.

We have also seen 3D-printing technology being used to produce entire boats in plastic, although this technology is still radical and very new for boat building.

Although there is often some reluctance to do so, there is no reason why materials cannot be mixed on a boat. Aluminium hulls with fibreglass cabin and decks have been seen for quite some time, while hardtops and cabin roofs are often made of aluminium, fibreglass, or polyethylene. On a smaller scale, unless you have a ‘classic’ wooden boat, you will probably find that your hatch covers are plastic, regardless of the boat’s hull material.

First welding attempt – no good!

For the DIY-er, making something with plastic offers some advantages: it won’t ever rot, it is cheap and never requires painting. However, there are some downsides too: plastic is harder to work with, unforgiving of mistakes (you can’t cover a botch up with some bog and a coat of paint!) and, at least in most homehandyman iterations, is not as strong as other materials. It is also slightly harder to source the correct materials, and there are many types of plastic which cannot be mixed or effectively joined together.

On a pre-lockdown trip out on the Hauraki gulf, carelessly leaving a hatch cover unlatched on my catamaran resulted in it swinging open while we were travelling at speed. The screws holding the hinges then gave way and the whole thing flew overboard. This was not noticed until we got back to the marina, and hence the cover, made of fibreglass, was lost. Since this was a custom size and shape for a 30-year-old fibreglass boat, there is no option to simply purchase a replacement. Something needed to be made.


The speedweld nozzle on my heat gun.

And this is where plastic comes into play. While I could have made a hatch cover out of marine plywood and painted it, or similarly made a pattern out of wood and then moulded a fibreglass replacement, I decided to have a go at making it entirely out of plastic instead. Last year I had a new hardtop made for the boat with 10mm thick plastic-welded polyethylene, and this has been great. It is rigid, easy to clean and requires zero maintenance. Hence, I decided to have a go at making a replacement hatch cover using this same construction method.

The first thing to decide was what type of plastic to use. Obviously, I needed something that came in a rigid sheet, and since we were in lockdown my options were limited. I managed to find someone near me who had some offcuts of PVC sheet from a bathroom liner. This was just 1.5mm thick, which is definitely thinner than ideal, but it was all I could get.

A bit of practice was needed, to get the speed and temperature right.

Other plastic options in normal times are acrylic sheet, readily available in clear sheets from major hardware stores, polyethylene (also called HDPE) and polypropylene. A quick Google search will show numerous plastic suppliers who can provide standard-sized sheets of a wide variety of plastic types.

PVC was probably the worst choice since it has the lowest melting point – potentially it could sag on a really hot summer’s day. However, any of the options would likely be adequate for creating a rainproof hatch cover. Acrylic and PVC can also be glued rather than welded – for most other plastics, finding a glue that will adequately adhere to them is almost impossible.

Unsupported, the sheet sagged.

The next issue is the plastic welding rod. This absolutely must be exactly the same type of plastic – different types simply won’t stick to one another. Therefore, you need to know the precise type of plastic before ordering the welding rod. Luckily, a plastic welding rod was classed as an essential item and I was able to order a roll online for contactless delivery. Of course, if you are buying a new sheet of plastic you can probably buy the welding rod from the same supplier.

And the last component required is a heat gun. Although you can buy specialised plastic welding guns which have a tiny heat nozzle, a cheaper option is simply a standard workshop heat gun with the smallest nozzle fitting that you can find. Even better, I had purchased a speed-welding nozzle at this year’s Auckland Boat Show. This fits to the end of a standard heat gun and allows you to feed the plastic welding rod into a slot as heat is applied. It also has a spine that enables you to accurately follow the nozzle down an edge or seam, producing a straighter weld.

The MDF jig to hold the sheets at the right angle.

So, now I had everything to start. Since my hatch cover serves primarily as a rain cover, I wanted it slightly angled down from the centre so water would run off. I worked out the pattern and cut four triangles which, when joined, would create a slight pyramid shape. Initially I used a small electric saw to cut the PVC, but later discovered that multiple passes with a very sharp utility knife did a neater job. I stuck the pieces together with some tape, turned them over so I could make the join on the underside, and started to weld.

The technique required is to heat the two mating surfaces at the same time as the welding rod, and then push the now-softened welding rod into the soft underlying surfaces. This fuses all three together and forms a solid bond. The speed-welding nozzle does this for you, and you just need to feed the rod and move the heat gun forward at the correct speed, according to the degree of softness of the material.


My first attempt was a complete disaster! The very thin PVC softened and sagged before it got hot enough for the welding rod to stick, and the adhesive tape melted and let go. In a couple of spots, I moved too slowly so the PVC charred. And when I tested my first weld it had very little strength! Time for a re-think, and a bit of practice before trying again.

The first critical change was that I needed to minimise the number of joins. Since the PVC was thin, I could crease it over a straight edge using the heat gun to soften it along the line. So my pyramid shape could be constructed from two pieces rather than four. This would give me just two joins.

Closer clamping worked better.

In fact, I could have cut the whole thing from one big piece of plastic and only have a single join, but my pieces were not wide enough for the full pattern that this would require. Instead, I made two large triangular pieces, each with effectively two smaller triangles, and creased the join between them. And now I just needed to make one long join, in two shorter parts, to bring the halves together in the desired pyramid shape.

The second point was that I needed the thin sheet to be flat and fully supported when welding, to avoid it sagging as it got soft. Since the joints were not flat but rather at a slight angle this necessitated a jig to hold everything at the right angle while welding. Some scraps of MDF were cut and screwed at an angle onto a base board to hold these in the right shape. After about half an hour spent practicing my technique on scraps of PVC, it was time for weld attempt number two.

The final weld – not too bad.

As the photos show, the second attempt was a lot more successful. I now had a good idea of the speed required, and there was almost no charring or discolouration. The weld was also much stronger, and when I flipped it over the top edge was reasonably neat, although far from perfect. There was still some warping along the second joint and the top side of that one also showed some discolouration. For the moment I decided this was adequate, but as soon as lockdown ends and the suppliers open up again I will re-make this with some 5mm thick sheet.

All in all, it has been an interesting exercise – low cost and with less work than it would have been to make out of wood. Now I have some practice and have my pattern worked out, it should take me about an hour to make the next version in thicker sheet. And the finished result should last forever – unless I again leave it unlatched and the blasted wind rips it off a second time… BNZ

Hatch cover installed.

Many ways of steering

Every watercraft built since the dawn of time had to be steered in some way.

In ancient times steering gear was usually some version of an oar that was held vertically, which eventually led to the development of a dedicated rudder. The rudder was controlled by the helmsman sitting in the stern of the boat using a tiller, a horizontal bar fitted directly to the top of the rudder post. We see these today in dinghies and in some sailing boats, large and small.

The advantages of this system include a very simple mechanism and direct, highly-responsive steering. On the downside, to operate the tiller the helmsman has to remain close to the rudder and steering the boat can be physically demanding, especially in bad weather.

A conventional helm with a wheel. This example uses hydraulic pressure to turn the rudder.

The next major development was the ship’s wheel, mechanically connected to the rudder. How the wheel is connected to the rudder varies. Early systems used ropes and pulleys or a mechanical shaft and gears. They allowed the wheel to be located near the front of the vessel where the helmsman had better visibility, far away from the rudder at the stern. Different sized pulleys or gears reduced the force required to steer, although at the cost of a certain degree of responsiveness. Early vessels had spokes sticking out of the wheel to grab hold of – wheels could be difficult to turn, especially in bad weather – and many traditional vessels retain this design.

Modern boats have largely continued using one of these two systems, although the mechanisms have changed. Ropes and pulleys made way for cables and more sophisticated gearing, before hydraulic systems and power assistance became available. More recently, electric actuators can be used to operate the rudder – the wheel now acts more like a control switch, with no direct force transmitted from the wheel to the rudder or motor. An advantage of hydraulic and electric systems is that vessels can have multiple helm positions, often one on the flybridge and one in the main cabin, providing greater flexibility for locating the helm station.

A rope and pulley system, actuated by a ‘steering stick’ in the bow moves the outboard motor fron side to side to steer the boat.

Surprisingly, though, this is not the only way boats can be steered. Anyone who has been to the Cook Islands or Tahiti will know the local fishing boats are steered with what can only be referred to as a ‘steering stick’. This is a vertical bar sticking up in front of the skipper, who is positioned in a snug helm position right up in the bow of the boat. Moving the bar from side to side turns the outboard motor, facilitating tight turns at high speed.

These systems were originally developed with a ropeand- pulley arrangement between the stick and the motor, but newer ones use a modern cable or hydraulic steering system. We even saw one with electric actuators on the motor, where the skipper used a small toggle switch to swing the motor left or right.

Tiller steering is still used today, especially on yachts.

The main purpose of this unusual steering mechanism is to sight-hunt highly manoeuvrable game fish. It was developed in Tahiti to chase down mahimahi. The fishermen literally chase the fish across the surface until they are exhausted enough to spear easily. In the Cook Islands these boats are used to hunt mahimahi by day and flying fish by night. To beat giant trevally to the flying fish, fishers need to be able to spin the boat around very quickly to match the movements of the fish.

But arguably the field of GPS and marine electronics has produced the most significant changes to boat steering. With the combination of electronic throttle control and powered steering systems, electronics can completely control both the direction the boat moves and its speed. Of course, the basics are not new – Autopilot systems have been around for decades, and many larger vessels have been steered using a joystick rather than a wheel for some time. What is new is the availability of this technology for vessels of every type – even smaller outboard-powered craft with a single engine.

HamiltonJet’s ‘MouseBoat’ control.

Joystick steering options started appearing on recreational vessels in 2005, when Volvo launched its revolutionary IPS pod drives. Since these drives are self-contained and turn inside their mounting using an electric actuator, their joystick control provided one-handed operation when docking, removing the need for complicated dual-shift, throttle and steering combinations. Since then, Volvo has shipped more the 30,000 units and now competing technology is available from Cummins, Caterpillar and ZF Marine.

The joystick got its next upgrade in 2007 when HamiltonJet launched its MouseBoat controller. Paired with its waterjet propulsion technology and proprietary blueArrow electronic control systems, this handpiece looks like a miniature boat that moves and acts much like a computer mouse. Instead of moving a cursor across a computer screen, moving the MouseBoat moves the vessel in the same way – forward, astern, or sideways. The MouseBoat also added a third axis, so rotating the device would spin the vessel the same way, whether traveling ahead or astern, or even in place.

Both these systems also provided a feature called GPS anchoring. This is where the electronics hold the vessel in an exact position, regardless of wind and tide, and without deploying an actual anchor. This is especially useful deep drop-fishing over undersea structures in deep water, where anchoring is not an option and positioning the boat is critical.

Volvo Penta made joystick steering mainstream with the introduction of IPS.

This system was originally patented in 1995 in the USA and first appeared on trailer boats when it was adopted by numerous manufacturers of trolling motors. These devices are spun around in their mountings by an electric servo, and being electrically powered, their motors already enjoyed electronic control.

But being able to control outboard motors in a similar way to the pod and jet drives was recognised as a gap in the market, one which Yamaha was first to fill with its Helm Master digital steering system in 2013. This system added joystick steering and directional control for boats with twin outboards. The key breakthrough for this system was controlling each outboard separately, with independent powered hydraulic steering rams and digital throttle and shift controls for each motor.

That means the boat can be moved sideways by angling the engines at 90o to one another and putting one in forward gear and one in reverse. Their joystick control also includes that rotational axis of movement, so the boat can be moved essentially in every possible direction. All of which simplifies manoeuvring around marina berths or getting lined up onto a boat trailer, especially in high winds or strong currents.

A ’ma’i ma’i boat’ in Avarua Harbour, Rarotonga.

Since then, the market has become a bit more crowded with Evinrude adding its iDock Intelligent Piloting System, Mercury its JPO (Joystick Piloting for Outboards) and Suzuki the Optimus 360 Joystick control system. The Optimus system is in fact a third-party solution developed by Dometic (formerly known as SeaStar), which is compatible with other outboard brands that offer digital shift and throttle control.

The most recent steering innovation, and the most exciting for the smaller trailer boat customer, has come in the switch from a conventional hydraulic steering (with its helm pump, engine control pistons and supplementary electric hydraulic pumps), to all-electric actuators. These remove the need for any hydraulic rigging and dramatically simplify the installation of the boat’s steering system. Although a conventional wheel can be retained as the main steering control, with a digital engine actuator the wheel becomes a completely digital unit. In two or more engine installations this simplifies the whole installation and improves the responsiveness of the digital steering system.

Yamaha’s electrically-actuated steering module.

More excitingly, though, the speed of movement of these digital electric actuators has also enabled sideways manoeuvrability for boats with just one outboard. The Yamaha Helm Master EX – launched in New Zealand last year – provides joystick capabilities for a single-engine vessel. Although it works as expected when moving forward or astern, it excels in close quarters and when trying to fit the boat into a tight space: the engine turns itself and changes gear automatically, moving the boat sideways through the water.

All the other features of digital steering can be added to the Yamaha Helm Master EX system – the EX stands for “Expandable”. The most popular is GPS anchoring, called Fishpoint on this system. This will hold the boat at an exact spot, pointing the same way it was when you pressed the button. So, if you see something interesting on the sounder, press the button and you will stay directly above it.

Yamaha Helm Master EX joystick steering even works with single outboards.

Of course, an autopilot is another great option, and Yamaha integrates into several major brands of multifunction displays. So, you can set your course and speed, press a button and the boat will drive itself to the spot. The vessel can also be set to automatically slow down upon arriving at the selected location, and then hold itself at that position once you get there.

Although the Helmaster EX is somewhat more expensive than a conventional steering, if you factor in that it eliminates all the hydraulics, negates the need for a bow thruster, can provide the same functionality as a low-speed trolling motor and includes an autopilot, the additional cost on a new boat is modest.

Of course, other manufacturers are hard on Yamaha’s heels. Already Dometic has developed an all-electric actuator, and you can be sure the engineers are busy integrating this into their Optimus system for single outboards. It won’t be too long before technology eliminates the struggle to get your boat onto a trailer or into a berth in strong wind and tides. Watch this space.

Bring it on! BNZ

Knowing your ropes and rode

Let’s get the first question out of the way: When it is ‘rope’ and when is it ‘rode’?

When you go to the marine chandlers or even the hardware store, you will not see any ‘rode’ for sale – you can only buy rope. But what it is called on a boat depends on where you use it. When you attach it to the anchor it becomes the rode. If you use it to tie the boat up to the dock it is a line. Attached to the mast it becomes part of the rigging, while the ropes that pull a sail up or down are called halyards. When tied to the front of a dinghy it is a painter. Arguably the only ropes on the boat are the tow rope and the rope to ring the bell, both absent on most modern boats.

Having cleared that all up, the term ‘rode’ actually refers to three components of the anchoring system: The rope portion, the chain, and the swivel. So, while you let out the rode to lower the anchor, part of that may in fact be the anchor rope. Confused? Never mind, most non-traditionalists don’t get too fussed what you call it – what matters is what it is made of.

And thereby hangs the rub, to dig out another old phrase that might be appropriate. Because the choice of size, material, and construction (braided, stranded or plaited) can make a major difference to the effectiveness of your anchoring system, and in particular the operation of powered anchor winches. Get it wrong and the winch will slip, jam or break off expensive pieces. Less seriously, you could spend up to thousands of dollars for a type of material or construction that is unnecessary.

Nylon rope is soft and curls easily around the gypsy.

Added to this is the current shortage of all manner of materials sourced from overseas. Marine supplies are also caught up in the global logistics issues caused by Covid-19, and sourcing the correct material may be difficult, expensive or even impossible. So, will an alternative product work or not? Let’s explore the options.

We will start by splitting the discussion between hauling your anchor by hand or with an automatic winch/ capstan (or windlass, depending on whether it is vertical or horizontal. We won’t worry too much about the finer points of this just now.)

If you still use muscle power to lift your anchor, even if you use a capstan-type electric motor to provide the main lifting power, then the choice is relatively easy and not too cost-prohibitive. There are four main considerations: Strength, floating characteristics, handling and price.

Polypropylene is stiff, usually brightly coloured and best used for mooring lines.

The most common synthetic ropes are made either of nylon, polypropylene or polyester. While there are also some exotic materials like Dyneema, Dacron and Spectra, these are mostly used by performance sailing vessels where weight and strength outweigh the considerable extra cost. And at the lower end there is one more option of polyethylene, but this is generally only available in smaller diameters and bright colours for ski ropes and similar water toys. In most circumstances it comes to a choice between just those first three.

NYLON is the most expensive of the three main contenders, and although the strongest when dry it loses some strength when wet. Nylon is heavier than water, hence it sinks, is extremely hard-wearing and is UV-resistant. It has a fair amount of stretch, which is good in an anchor rope, since it acts like a shock-absorber to reduce jarring as the boat bounces around on the anchor. And for a manual anchor rope, nylon is also the softest on the hands while remaining easy to grip. A good quality nylon anchor rope will last for many years and is a wise investment.

POLYESTER is stronger than nylon when wet, equally resistant to wear and sunlight, and also sinks. It can be somewhat cheaper than nylon and is often used for permanent moorings where the strength is the most important criteria. However, it has very little stretch, and for this reason alone is not generally preferred as an anchor rope.


POLYPROPYLENE is the weakest and cheapest of the three, also has a reasonable amount of stretch but is the only one that is lighter than water and so floats. This rope is slippery when wet and can be hard on the hands, and it also melts at fairly low temperatures – a hot engine exhaust may be enough. The low price is probably the main reason it is offered in some anchor packs. However, the fact that it floats is a disadvantage for anchoring since a floating line is more easily tangled around a propeller.

We did a quick comparison of different specifications of the popular 12mm diameter three-strand rope packs available at most marine suppliers, as listed below. Note we have not listed prices, since these varied greatly, but in general the cost will run in descending order from nylon to polypropylene.

So, for a small boat with good old muscle-power as the anchor winch, there really is no decision: go with nylon. The standard three-strand laid rope is the easiest to handle with bare hands or even gloves, so no need to fork out for braid or plaited types. This also applies to non-automatic capstan winches, where you must manually hold the rope tight against the round drum – nylon three-strand is the best option here as well.

Electric capstans work better with some ropes than others.


If you have an automatic anchor winch the decision becomes a bit more complex. Although the same rules apply for the material used (i.e. nylon is best), another factor comes into play – the way the rope is constructed. This is important because of the most critical component of an automatic anchor winch, called the rope and chain gypsy. This is the notched wheel that has different areas to grip both the anchor chain and the rope. And gypsys are very, very picky – in many cases they will only work properly with one type and diameter of rope.

When talking rope for an anchor winch, there are usually only two types of construction to consider: The common three-strand laid rope, or eight-strand plaited rope. The smooth and perfectly round 24-strand yachting braid is seldom used in winches because it is too smooth for the notches in the gypsy to grip.

Maxwell is one of the most popular brands of vertical and horizontal winches, with its RC series going from the RC6 to RC14, depending on the size of your boat. For most of its range the manufacturer’s recommended rope is a three-strand laid rope in the appropriate diameter for that model of winch. However, many of the models will also work with an eightstrand plaited rope, while the HRC8 horizontal model will ONLY work with the specified 14mm eight-strand plaited rope.

Another popular brand of recreational anchor winch is Lewmar, and its recommended rope is a “medium-lay threestrand soft nylon”. The ‘Pro-set’ brand of three-strand nylon rope from American supplier Samson is even commonly referred to as ‘Lewmar rope,’ since it exactly conforms to the Lewmar specifications.

Muir winches are designed to use their own brand of threestrand nylon rope, which also have a water-repellent coating to make it slick and keep it clean. The Italian brand of Quick winches also recommends three-strand but will similarly work with the eight-strand as well.

So, since many of these will work with either type, the question then is which is the best option? And as usual there is no simple answer. When placed under extreme load (like when the anchor snags and you are using engine power to try and break it free), a three-strand rope can partly un-twist and individual strands can jam themselves tightly in the slot in the gypsy. This may then require judicious force and the appropriate swear words to clear out. This cannot happen with an eightstrand plait since it has counter-twisted strands and so will not un-twist under load.

On the other hand, the three-strand type is most manufacturers’ recommended type for most (but not all) models and is cheaper and more readily available than eightplait. So, unless your model of winch will ONLY work with one type, you can make the decision as to which you prefer. Eightplait is harder to splice, but easier on the hands if you ever need to raise the anchor up by hand.

Of course, if you have a drum winch, like those from Stressfree and Viper, then the type of rope is far less important since they wind the rode around a drum rather than grip it with a gypsy. Most drum winches use a much smaller diameter of rope, and super-thin Dyneema braid may even be used to get a greater total length of rope on the drum.

Luckily there is a choice of rope that will work for most models, because with the current global supply issues, certain ropes are in short supply. However, if your local marine supplier does not have the correct size and type, you may need to be patient until they get more stock, or you can try and source it over the internet with the associated international shipping costs and uncertainty. BNZ

Boost your phone

Boaties venturing offshore know how quickly a phone loses signal bars – and data apps become patchy at best. The combination of poor signal strength and the phone’s low antenna height limits communication with the closest cellular tower. But there is a solution.

Mobile phones have become an integral part of our lives and with services like Google Maps making printed roadmaps pretty much redundant, data is essential.

Similarly, when you’re out on the water, navigation aids, real-time weather updates, sea surface temperature maps and marine apps all rely on cellular data. So you need to boost the signal.

Installing a mobile booster antenna on your boat is a simple, relatively cheap solution, but there’s an inherent problem: no modern smartphone allows you to plug an external antenna directly into it. This means you also have to add a mobile router device to create a WiFi hotspot, running off its own network SIM card. You then have to configure your mobile to connect to that hotspot, and it only carries data – voice calls and text messages don’t work as they’re not carried over WiFi.

The Blackhawk cellular antenna, and right, the high-gain Omni marine antenna.

The best solution would be your own private cellular base station, something that will move around with your boat and provide five bars of cell coverage to your mobile device. That base station can use a large external antenna mounted high on the boat to greatly increase range and signal strength from even the weakest and most distant land-based cell tower. It should provide both 3G and 4G coverage (and ideally be 5G-ready as well) so your mobile phone can use whatever signal is best for voice, text and data services.

Another benefit of a local base station is that your mobile device’s battery will last much longer. When a cell phone detects a weak signal it boosts its own transmitting power, which considerably reduces the battery life. You might have noticed this out on the water: your cell phone runs low on battery power far faster than it does around home. With a strong local signal it will only need to use minimal power.

Powertec is an Australasian distributor of marine cellular booster solutions, with an office in Auckland. It provides a range of solutions for rural, industrial, camping and marine installations. The Cel-Fi Mobile Signal Repeater is the heart of its solution, and the technology was exhibited at the recent Fieldays expo at Mystery Creek.

A typical installation on a launch.

Made in California, the Cel-Fi system combines three elements: an omni-directional high-gain external antenna, the Cel-Fi Go2 unit, and an internal cellular antenna to provide coverage everywhere in your boat. The external antenna operates much like a VHF antenna and is mounted as high as possible on the boat roof or on a mast. It talks to the cellular network and has a claimed range of up to 100km.

Georgia Crowley, Account Manager for Powertec in New Zealand, gave us a rundown of the system. They have been targeting the rural market in New Zealand, where mobile coverage is often either poor or non-existent. By installing the high-gain antenna in a suitable location farmers can achieve coverage over a much wider area.

Crowley says the marine market is another growth area, where the effective mobile range has declined ever since Spark (previously Telecom) decommissioned the old 025 network. Many commercial and game fishing boats had car-model base stations installed on board and have enjoyed excellent coverage even quite far offshore.

But the increased data speeds of the newer technologies (first 3G, then 4G and now 5G) each come with the trade-off of ever-reducing range. This is countered on land by building more cell towers, but that’s hard to do out at sea. So the solution is to take your own base station with you.

The Cel-Fi Go2 Network Repeater has a USA NEMA 4 rating, which is the equivalent to IP65 but with additional corrosion resistance. It can be installed just about anywhere on the boat and does not require any special protection.

The last component of the kit, the cellular antenna, needs to be suitably located so all the cabins on a larger boat get good coverage. This is really only an issue for larger vessels with multiple cabins. They have a surface mount option for this element – it’s a nice, discreet solution.

Once installed, the system essentially operates effectively as its own cell site – there is NO re- configuration required on your mobile devices. The device simply works as before, with all functions (data/ voice/text) fully operational.

It is network-specific – the Cel-Fi unit needs to be pre- configured for one of the mobile networks – Vodafone, Spark or 2Degrees. You install the unit for whichever is your network provider. But there are no running costs and all network charges are to the account of the mobile devices as per their own SIM cards.

The Powertec unit isn’t a cheap solution, coming in at a touch over $2,000 for the marine bundle, but the base unit can easily be disconnected and taken off the boat when not in use. It can then be multi-purposed for other applications – say at a bach or on a caravan.

With the extended range provided by the unit, it’s perfect for boats heading reasonably far off the coast, such as game fishing boats as well as commercial fishing vessels. Powertec also has a lower-cost option that provides either 3G or 4G coverage but not both at the same time – the unit has to be configured for the chosen option.

The Cel-Fi Go unit is a simple solution that will help you receive data further offshore.

3G will give greater range for voice and text and is suitable for low-data applications. But 4G provides a higher speed for data-rich applications – though it has a lower effective maximum range. The unit is also 5G-ready, for when our network providers roll this out beyond a couple of cities in New Zealand.

Powertec recommends that you have the unit installed by one of its accredited installers around the country, to ensure the device is achieving the best coverage possible. But its marine kits are pretty much plug-and-play, and come pre-bundled with all the connectors necessary. There is also a quick-start guide, so a suitably competent DIYer can easily install the components.

The caveat to this relates to the size or construction material of your vessel, since the location of the cellular antenna can be critical to getting good coverage in all areas of the boat. Aluminium does a very good job of blocking cellular signals – wrapping your phone in aluminium foil is one of those ‘hacks’ that litter the internet.

So if you have a larger boat with alloy (or steel) in the cabin walls you may need to explore various locations for this component, and this is where an experienced installer would certainly add value. This is not an issue for boats with wooden or fibreglass cabins, since cellular signals pass through these materials quite easily.

Although our cellular coverage is pretty good when close inshore, this solution would be perfect for anyone who heads further out or who takes their boat to more remote locations around the country. BNZ

Bigger vessels may require a more extensive installation–but the principle’s the same.

The case for AIS

Retrofitting an AIS (Automatic Identification System) to your boat is relatively inexpensive and easy, and it might make a significant difference in a rescue situation.

Trampers heading out into the back country usually carry a personal locator beacon (PLB). An EPIRB (Emergency Position Indicator Radio Beacon) uses the same technology and no boatie should head out without one. In both cases, activating the beacon transmits a distress signal – together with its precise GPS co- ordinates – to an overhead satellite network.

There are even compact waterproof locator beacons for kayakers and swimmers, and with a suitable housing some PLBs can also be taken underwater by scuba divers. The locator beacon technology is reliable, compact and very precise. Unfortunately, the strong point of the technology is also its greatest weakness – it’s based on a satellite signal.

The Simrad RS40 VHF with Class B AIS was our alternative option.

This means beacons can be used in remote locations with zero radio or mobile phone signal. But it also means the alert has to be passed through the global satellite response system, and then routed to the National Rescue Co-ordination Centre. The centre then decides which local agency (Police, Coastguard, Mountain Rescue, etc) is best placed to deal with the issue, and an appropriate search and rescue operation is initiated.

Apart from the slight delay, the main issue with this for boaties is that other nearby vessels will be completely unaware there is someone in trouble until Coastguard puts out a VHF call. Usually, the best source of help is the closest boat. By the time a Coastguard vessel arrives it may be too late.

A secondary issue is that an EPIRB or PLB is strictly for emergency use. It initiates a full SOS alert which cannot be cancelled by the initiator. Once the process starts there is a formal protocol to be followed even if the beacon is turned off, and there are potential repercussions for false alarms.

There is no way to use this system as a simple ‘Hey, come fetch me’ type signal, which may be all that is required. We faced this situation a few weeks ago while scuba diving in the Hauraki Gulf.

Selecting the symbol on the details of the target, including bearing and distance.

With the moderate current one of the divers had drifted a fair way from the boat before surfacing. He could see the boat but those on board couldn’t see him, and he was too far away for them to hear him shout or whistle. The angle of the sun also made it difficult to see his surface marker buoy.

This caused a major panic on board with a full callout to Coastguard resulting in a local rescue boat being dispatched, its fixed-wing aircraft taking off and even the police helicopter being redirected our way.

In fact, this was unnecessary in the end because a nearby boatie joined the search and shortly afterwards found our missing diver bobbing safe and sound on the surface some way from us.

The Nautilus Lifeline Marine Rescue beacon.

The only issue was he had run out of ways to try and attract our attention. In this case a PLB would certainly have initiated the same rescue scenario, but what he really needed was a simple way to tell those on the boat where he was.

Which is where AIS comes in.

The marine Automatic Identification System is carried by all commercial shipping, and you can track the position of any vessel in real-time at On that website you can zoom in to your region of New Zealand and see ferries, container ships and other commercial vessels moving around. The data is updated every few minutes and clicking on any of the targets gives you more information about the vessel.

Simrad’s RS40 VHF comes with an integrated AIS receiver.

AIS has two flavours: class A and class B. It is the class B version of AIS, which operates over the VHF radio frequencies, that is useful for inshore waters. Firstly, an AIS receiver can be installed in recreational boats at a very modest cost. Secondly, it need not be a full emergency – an AIS-based locator beacon has two modes, one of which simply transmits the beacon’s current location. The second mode appends a distress signal to the location and is used for an emergency situation.

So, in our case when our diver popped to the surface and was unable to get our attention, he could have simply activated the ‘location’ signal on his AIS personal beacon. This would immediately display his position on the boat’s chartplotter, and we would know exactly where he was.

If we had pre-programmed the ID of his locator into the unit it would even show us his name rather than just the generic ID. The beauty of this system is that his location would show on any boat in the area with AIS capability, either on their chartplotter or VHF radio.

With this experience fresh in mind, we set about implementing an AIS solution.

The finished installation. Just need to seal the cable holes. Pretty straightforward.

First on the agenda was to source appropriate locator beacons for the divers. There are two solutions readily available in NZ – the Nautilus Lifeline and the McMurdo Smartfind S10. Both are compact, waterproof to well beyond maximum recreational diving depths, and have a five-year battery life.

The Nautilus is more compact and slightly cheaper, while the Smartfind is perhaps slightly easier to activate and also incorporates a flashing indicator light for night- time use. Needing a couple of these units, cost was our deciding factor – we purchased the Nautilus units through our local dive shop, but they are also available online from local distributors

Next, we needed an AIS receiver on the boat. We could have gone for the best solution and installed a full AIS transponder, which is then integrated to our chartplotter. A transponder transmits a signal to tell other vessels where we are and also receives signals from other AIS units. We have previously reviewed AIS systems from local manufacturer Vesper Marine, and this would be the ideal solution.

But this was overkill for our specific requirements and also exceeded the available budget. Instead, we looked for a lower-cost solution – a receiver-only option. The AISR120 receiver (manufactured by Australia’s GME), is available from all marine chandlers and even a few auto spares shops. At around $350, it’s a relatively modest outlay, although it also needs a dedicated VHF antenna (or an aerial splitter to share your VHF’s existing antenna).

The red, circular icon indicates the beacon’s location.

The unit has a built-in GPS antenna, though you can connect it to a suitable external GPS antenna if your installation location does not have a clear view of the sky. It has a NMEA- 2000 port and also a NMEA0183 output for older chartplotters, as well as an optional USB interface for connecting to a laptop computer.

Another solution we considered was upgrading our existing VHF to something like Simrad’s RS40 VHF radio with integrated AIS receiver. At just under $800 this would be the easiest in terms of installation – it simply replaces your existing VHF and plugs into the same antenna.

An optional NMEA-2000 cable then connects this unit to your chartplotter, and it has the added advantage that you will get the AIS signals on your VHF radio screen even if the chartplotter is turned off. The unit also works as a stand-alone AIS receiver if you do not have a compatible chartplotter. But in keeping with the minimum costs objective, we opted for the GME.

The AISR120 unit was a simple install. We considered the wide dash area inside the main cabin, but as the unit has an IPX7 waterproof rating we instead fitted it up on the flybridge. This gave the unit a clear GPS signal, and both 12V power and NMEA-2000 connections were close by.

Connecting the VHF antenna was the only complicated part, since an AIS-compatible VHF splitter is not the same as the usual VHF/FM splitter used to run the stereo off the same antenna as the VHF.

The Smartfind S10 was another option for the diver’s beacon.

Signal loss will occur unless you implement an active splitter, which is an additional cost. Luckily our boat had two standard VHF antennae already installed, one of which was redundant and could be repurposed. Total installation took less than 30 minutes.

Configuring the system couldn’t be easier. Our Lowrance chartplotter simply recognised the AIS receiver, and we immediately began receiving AIS signals from nearby commercial vessels. Testing the Nautilus involved turning it on and pressing the test mode button, and within 45 seconds it had obtained a GPS fix and transmitted its position.

Our chartplotter instantly showed the location and beeped a warning and continued to display the beacon’s location even when we took it some distance from the boat. Selecting the target icon gave us more details, including the bearing from us to the target and its distance away.

We were able to customise the icon, and give the AIS device a user-friendly name, but have not bothered. Note the AIS beacon will default to a different icon from commercial shipping, so it’s easy to identify even if there are other vessels around.

Job done, and now we just need to make sure divers pop a beacon in their BCD pocket before heading overboard. BNZ

Caring for your anchor rode

When did you last wash your anchor warp? Not a common maintenance item, but something that may be worth considering, especially if your boat’s more than 10 years old.

A recent trip out on my buddy’s boat we anchored in deeper water than usual, and it transpired his anchor line was slipping on the chainwheel. Instead of the winch’s teeth gripping the rode's sides, the hard, stiff line simply slipped over the chainwheel without engaging into the slot. Almost no holding power and, left unchecked, all of the rode would have slipped out.

This was easily dealt with at anchor – we simply put a few wraps of warp around the bollard – but raising the anchor did require some additional manual assistance. This is a risky business for fingers – we had to try and push the line into the chainwheel slot without snagging line or fingers. Luckily, we managed it while keeping all our digits.

Back at the marina we realised that years of sitting in the anchor well, wet from salt water and with the chain resting on top, the rode had become caked with salt crystals, pieces of rust and other random crud. What was originally a soft and pliable product was now stiff and hard. Looking at the splice on the chain end showed that this too was in poor condition, but with those hard fibres re-splicing it would be quite a job.

Buying new anchor line was the obvious solution – quick and simple if you have a modest anchor setup. But my own launch has 175m of 16mm braided line. A replacement would cost me well over $1,200 – not a pleasant prospect. Was there a cheaper (but still safe) solution?

Well, yes – the rope could be cleaned, as a quick Google search revealed. But after years of neglect it might be a daunting project. The first thing was to remove the rope, and in the process examine every metre of it and the anchor chain, and in particular the joins between components. In my case I decided the chain was too badly rusted to salvage, so I simply cut it off and discarded it for later replacement.

I also laid out the rope carefully and discovered a major abrasion about 10m along its length. There was also a splice just short of 20m along, which always caused issues when going through the winch. Since I had a long line, I cut off the troublesome 20m section, still leaving me with over 150m of undamaged length. But the rode was badly discoloured and very, very, stiff. Oh, and it smelled very fishy...

I took it home and tried to get rid of the salt. I left it soaking in a big tub of fresh water for two days, replacing the water a few times. Then I added some Salt-Away and left if for a further 24 hours, stirring every now and then. After this the rode felt considerably better, and there was a lot of silt sitting in the bottom of the tub.


The rode was still very dirty, so a proper wash was called for. But washing it is certainly not a job for a home washing machine. Apart from losing every brownie point I may have ever earned on the domestic front, it simply would not fit into the drum of our machine.

Luckily, many self-service laundromats have a range of big, bigger and mega-big washing machines. The one closest to us had a couple of super-big machines with a 28kg (dry) load limit, which easily accommodated the rope. Would they allow me to wash a smelly old rope, rather than clothes?

I chose a day and time with few people in the laundromat and went there loaded up with detergent. But I discovered that the Liquid Laundromats franchises have a special pet-blanket cycle on their very big machines.

This option has extra pre-wash and rinse cycles and indicated it could cope with large and smelly loads. The brown colour of the wash water revealed how much muck there was in the rode’s fibres. Fabric softener was added to the final rinse water, to soften the fibres.

The process was finished with a tumble dry on medium heat for 45 minutes, not trying to completely dry the rode but to get it touch-dry. You need to be careful not to use maximum heat, as the 87° hot air could seriously weaken the rode.

The line was now visibly cleaner and almost back to the original colour. Note: do not be tempted to add bleach during the wash cycle as this can also weaken the fibres.

At home I completed the drying process by looping the rode over the frame of the wash-line, and by the end of the day it was bone dry and ready to work with. It was now soft, pliable and would be easy to splice. The cuts ends had frayed slightly, but these were easily cleaned up.

With a dry rode I also had an opportunity to re-mark it. A common trick is to mark a strip every 10m along the anchor line with a different colour, indicating the amount of rode paid out. Paint only sticks on clean, dry rode, and you want to try and get the paint right into the weave so it won’t be rubbed off by the chainwheel.

With five different cans of spray-paint available, I used a different one until I got to 50m, then started again and made a double-strip for 60m, 70m and so on. At 100m I started the colours again with a triple band. I made a note of which colour corresponded to which length and created a sticker to place on my dash next to the anchor switch.

After buying a new length of anchor chain (one and a half times the length of the boat) to match my winch’s chainwheel, it was time to replace everything. Splicing braided line onto chain requires a special technique, but once again a quick Google search showed the steps required.

If you’re not confident doing this yourself there are a number of local suppliers who will splice your line for a modest fee. The important thing is for the connection to be sufficiently streamlined to pass through the chainwheel without snagging or slipping.

Back at the boat I used the opportunity to wash out the empty anchor locker, finishing with a scrub using the desk wash and a scotchbrite pad. I found a surprising amount of muck, not to mention a few wayward nuts and bolts...

The last step was to service the winch, an often-neglected maintenance item. I removed the chainwheel and replaced the plastic stripper than cleans the rope out of the slot. Although this was still functional it was showing some wear, so this was an opportune moment to fit a new one. The various shafts were cleaned and lubricated and the chainwheel replaced ready to handle the clean rode and new chain.


In the now clean and dry locker I used a bowline knot to tie the end of the line to the eye inside the locker. The choice of knot is important – a bowline allows the rode to be easily untied, without having to cut it, should we ever seriously snag the anchor. We can then drop the rode under a float to be retrieved later on. And a bowline is a strong knot that will not self-loosen.

I laid the rode in reverse sequence to the way it would deploy, creating big soft loops across the bottom of the locker. The chain too was stowed in gentle loops inside the rope loops, so it would deploy easily without tangling. The end of the chain was fed up through the hole into the winch and out around the chainwheel.

Finally – time to re-attach the anchor to the chain, using a swivel. Again, I first checked everything for rust, especially in the hidden recesses. Finding it all good, the anchor was attached and hung over the bowsprit. A quick test of the anchor functionality confirmed everything worked perfectly.

Job all done, and total cost around $250 including the new chain and winch stripper, plus $20 in laundromat costs. BNZ


ENGINE COMPUTERS: A curse or a blessing?

Everything seems to be controlled by a computer these days, including boat engines. Those of us with more than a few decades under our belt will remember the days when starting up an engine – diesel or petrol – required a few manual steps. Not any more, writes Norman Holtzhausen.

When did you last have to use the choke lever before cranking the engine, and push it back slowly as the engine warmed up? With diesel engines, do you remember holding a button for about 10 seconds to heat the glow plugs before cranking?

In either case the engine would usually fire up in a cloud of smoke, and you’d leave it idling for a few minutes while it warmed up (and stopped smoking), before applying any load.


Modern engines are much simpler – turn the key (or push the button) and they start. Instantly, every time. Without any smoke. And you can drive off pretty much immediately, without having to wait for them to warm up.

Modern boat engines no longer create clouds of fumes and generate far less noise and vibration. They have two other significant benefits: they consume considerably less fuel than their predecessors, and smaller (and lighter) engines generate the sort of power that previously required a bigger displacement.

Which is fantastic – until they don’t work any longer. You turn the key and get nothing – maybe a couple of beeps and a dreaded computer fault code on the gauge. This doesn’t actually tell you what is wrong.

Troubleshooting is now a standard sequence: check the battery, turn the engine master switch off and back on again. Like a desktop computer, the first step in troubleshooting is a reboot. If you’re lucky it clears the fault. If not you switch to the second approach – unplug and re-plug all the computer cables.

So many components on a modern engine are now directly controlled by a computer. How is it that a diesel now starts instantly? Because the computer senses the temperature, injects just the right amount of fuel into the engine at precisely the right time to initiate ignition. And then it automatically adjusts the amount and timing to keep her running as she warms up. But when the computer is uncooperative, nothing works.

Arguably, in the good old days things were simpler. A diesel engine needs fuel, air and a way to turn it over. With enough cranking it will eventually start. The petrol equivalent is a little more complex – it also requires a spark, of the right size and at precisely the right time. But for both a competent home mechanic with a few basic tools could do a good job of diagnosing the fault and correcting the issue.

Of course, this did require a degree of experience and competence with mechanical devices, a comprehensive set of tools and knowing the location of all the critical components on the engine. And invariably dirty hands and oil over the deck. Not so with a computer.


Manufacturers of modern engines seem to go out of their way to make it hard to diagnose a fault, providing codes rather than actual details. The engines often require proprietary computer interface cables, and it’s hard to make sense of the numeric code without an actual computer to plug in to it.

But there is a way to make sense of a computer code/fault that doesn’t clear – a workshop manual. Not the Owner’s Manual, but the detailed, technical manual that lists the fault codes and their causes.

This can take a bit of finding but thanks to Google these are available for just about every make and model of engine. Depending on the manufacturer, the manual may have quite detailed and helpful steps for troubleshooting and rectifying the problem, even showing you exactly where on the engine the offending component is. Print a copy and keep it on board!

Armed with this weighty document, when you suddenly get say, a ‘MID 164 PSID 95 FMI 2’ code, looking it up will identify it as a fault with the throttle lever not being detected properly. In the case of my Volvo Penta D4-260 engines, rectifying this is a simple process of re-calibrating the throttle lever positions.

The ECU, which contols the engine.

Previous faults have also been easy to pinpoint (fuel pressure sensor, water detected in fuel, and others) and although some are more complex to rectify the computer code at least identified the problem.

One downside of all these electronic sensors is that you cannot always tell if the device is faulty, or whether the sensor is telling you there’s another problem. In my case the fuel pressure fault turned out to be a faulty sensor, which required a replacement, while the water-in-fuel was a valid issue that I needed to clean.

In both cases – without the computer – I’d simply have been aware of the engine losing power, with no simple way of knowing what was causing that loss. The computer told me exactly what to investigate and where to find it.

Of course, computers themselves can also go wrong, and unfortunately you cannot just pop down to the local IT store and get a replacement. The modules are proprietary, often specific to the model of engine, and can be eyewateringly expensive.

They also require programming, which needs an authorised agent with the appropriate tools. And because they’re so model-specific they may not be stocked by the local agents, so there may be some lead time to get a replacement. Luckily, they don’t fail too often, since they are usually fully-sealed units, and are relatively easy to access and replace.


Most engines have at least two (sometimes three) elements to their computer control systems:

• ENGINE CONTROL UNIT (ECU, also called ECM)– is the module located on the engine itself. It controls the components such as the injectors, fuel pump, oil pressure, water temperature etc. It also receives inputs from the multitude of senders and sensors on the engine

• THE HEAD CONTROL UNIT (HCU) – usually located at the helm. This is the module that the electronic throttles, gauges and NMEA-2000 interfaces plug into

• POWERTRAIN CONTROL UNIT (PCU) – it communicates to both the HCU and ECU. Note that some engines integrate the PCU and ECU, while others have two separate components. The PCU often controls the gear shift, power steering (if fitted) and external sensors like the fuel tank level.

These units are generally joined by what is called a bus cable – basically a data cable that shares digital signals between them. Although the bus connectors are waterand dust-resistant, they may occasionally develop a poor connection. So unplugging and re-plugging a connector is a good troubleshooting tip, especially if the fault code translates to something about “communication failure”.

Although one of my engines recently experienced a complete PCU failure (which cost $4,000 to replace), I still wouldn’t consider reverting to the old mechanical engines originally installed in my boat.

My current engines (four-cylinder, 3.9-litre diesels) are each 150kg lighter than the previous six-cylinder 5.8-litre units, yet each develops 50 more horses. Although they have a slightly lower torque curve, a supercharger (in addition to a turbocharger) helps them get through that mid-rev range and the boat gets up to cruising speed without trouble.

And after installing them overall fuel economy improved by nearly 20%. This was a combination of the lower weight, causing the boat to sit slightly higher in the water (less drag), and the lower internal friction losses due to four rather than six cylinders.

But the main factor was undoubtedly the very precise control of the fuel injection process provided by the ECU. So almost no fuel exits unburned through the exhaust, and the power output is much closer to the theoretical maximum energy available per litre of fuel used.

Of course, all of this doesn’t stop me swearing whenever I get that dreaded beep at the helm. But I then remind myself that the computer code enables me to pinpoint the problem and prevent a minor issue becoming a major one later.

And overall, this means less time fixing major engine issues and more time on the water. BNZ


Spot the hazards - Norman Holtzhausen

With the shorter winter days rapidly approaching, boaties are more likely to spend at least some of their trip in the dark. Getting in and out of marinas/anchorages is fraught at the best of times, let alone when you can’t see hazards or channel markers. Use a spotlight.

It’s illegal to have very bright, front-facing white lights on your boat while underway if these prevent another boat from seeing your coloured navigation lights. Running at speed with ‘headlights’ isn’t allowed.

But a bright spotlight may be used when coming into a berth or anchorage. Because the hazard is not always in front of you, having a controllable light that can be pointed anywhere it is an advantage. So, if you want to retrofit one, what’s currently available in New Zealand?.

Bottom of the pile, in both cost and complexity, is a powerful waterproof torch. Although these don’t compare with specialist spotlights, they’re cheap, readily available and spare batteries can be kept on hand. The popular Eveready Dolphin model can be sourced from any hardware store or supermarket, and its 200-lumen output is good in an emergency.

A far better option, though, is a handheld rechargeable spotlight. Most marine chandlers have a variety of options, ranging from 12V plug-in models through to battery-powered standalone models. Both halogen bulb and LED models are available, with the halogens being generally cheaper but also consuming more power.

My favourite is the 45-watt rechargeable LED spotlight model available from Jaycar Electronics, which is IP67 waterproof and also floats. It can be recharged through a 12V socket, and the manufacturers claim an astonishing 4,500 lumens of light.

A wrist strap helps prevent it from being dropped overboard and included in the package is a clip-in bracket to allow it to be used hands-free. The manufacturers claim a run time of more than 75 minutes on a full charge, which should be enough to get you home safely.

The issue with a handheld solution, though, is that you need one hand to hold and direct the light. This can be a problem for a solo boatie trying to steer at the same time. Also, you really do NOT want to be directing a spotlight through a glass window. Trust me on this – these units should only be turned on outside the confines of the cabin – inside, you will at the very least temporarily blind yourself!

This could be an issue if it is raining and you don’t want to open the window or hatch, but of course those are precisely the conditions when visibility is limited and you’re most likely to be needing a spotlight.


A better solution is an externally-mounted spotlight. The fixed-mount versions will cost about the same as a good handheld and need to be permanently mounted on a cabin roof or deck. Before you commit to a location, however, be aware of reflections off shiny surfaces like a bow rail, which can render the spotlight useless due to the glare.

Ensure the intended mounting point is either low and below, or forward of any stainless surfaces. A roof mount is a better solution (since this complies with maritime regulations) but ensure you place it far enough back from the edge of the roof (to cast a shadow over the bow railing and prevent that reflected glare).

When choosing a fixed-mount option, you can opt for either a narrow-beam ‘spotlight’ (it will project the light further but narrowly), or a wide-beam ‘floodlight’ which will light up a wide expanse. Both have their advantages – the floodlight is ideal for finding a mooring in a crowded marina with multiple hazards. On the other hand, a spotlight may be better for trying to navigate landmarks, such as when going through a channel at night.

Another variation on the fixed light theme is the lightbar, which can mix both types of LEDs into a long strip of intense illumination. Hella Marine has a range of lightbars, with its Sea Hawk 470 units providing options of either spot, flood or mixed LEDs producing up to 2,700 lumens per bar. And if that’s not bright enough, the bars can be stacked together for even more power.

At the top of the range are the permanently-mounted but remotely controlled searchlight-style lights. Most of these can both swivel from side-to-side and tilt up and down. Most modern options come with a wireless remote control unit, although wired helm controls are also available.

With the wireless option the light unit itself only needs a single cable running to it from a suitable power source, and the wireless remote means it can be operated from anywhere on board. Additional remotes can also be purchased, so a twin-helm boat can keep a unit on hand at each station.

These controllable lights may represent a considerable step up in price from the handheld and fixed units, and again both LED and halogen-bulb units are available. The halogen units, such as the $599 model from Marinco, generally have a brighter and narrower beam of light, more akin to a spotlight. The manufacturers claim a 300m beam range for this unit, and of course it is fully water-resistant to IP56 standard.

The nature of LED technology means these units usually illuminate a wider area. The MaXtek remote control LED spotlight from Absolute Marine, for example, has a beam projection range of about 75m but produces a much wider pool of light. The total light output from this unit is 1,600 lumens and it is IP67 waterproof rated.

One benefit of the mounted units is that most have an SOS button, where the light will flash the international distress signal (SOS in Morse Code) continuously if you are in trouble. Another useful feature when searching for something is the auto-sweep mode, where the searchlight will sweep automatically from left to right and back again without needing anyone to operate the remote. Again, useful if you are coming into an unfamiliar area and looking for any hazards.

And if this still isn’t enough for you, Hella Marine also has its Power Beam LED floodlights, which come in both close-range and long-range versions. These produce an insane 7,800 lumens, while consuming just 85 watts of power. To put this in perspective, the landing lights on a 747 airliner outputs around 8,000 lumens!

Just a reminder, though, that it is your responsibility to make sure your boat complies with the maritime rules regarding navigation lights. If your forward-facing white lights are bright enough to prevent someone seeing your red and green navigation lights, they should not be used where there are other boats moving about.

In general, any forward-facing white lights should be located at the masthead, or as high as possible on your boat, while the coloured sidelights are mounted lower down.

Stay safe out there!