BOAT REVIEW Sealegs 8.5 Alloy Cabin

July 2019 Trailer Boat Reviews
Words by John Eichelsheim, photography by Kimi Knight
Build Quality
MODEL Sealegs 8.5 Alloy Cabin
DESIGNER Sealegs International Ltd
BUILDER Sealegs International Ltd
LOA 8.5M
BEAM 2.31M
ENGINE Yamaha V6 250hp
Weight on Trailer -1 kg
Max Horsepower 250hp
Passenger Capacity 6 people
DEADRISE 16 degrees
  • Well spec'd, comfortable and nicely appointed.
  • Very stable at rest and dynamically
  • Top speed of 39 knots
  • Suitable for serious fishing and diving
  • Best Sealegs all-rounder so far
  • Locating AES machinery in transom free up cockpit

Sealegs’ new 8.5m Alloy Cabin take’s the company’s aluminium recreational range up another notch, and this one’s colour scheme is certainly designed to catch the eye.



Manufactured at Sealeg’s North Shore facility, the 8.5m Alloy Cabin is based on an Innovision hull design featuring a flared hull with a relatively plumb bow, a sloping foredeck, sturdy beltings and noticeable tumblehome aft. Deadrise is a modest 16 degrees at the transom, but the fine entry, relatively long waterline length and plumb bow ensures a soft, comfortable ride.

This model takes full advantage of Sealegs’ all-wheel-drive Amphibious Enablement System (AES) capabilities, which in this guise is rated to carry up to 3,000kg. Sealegs has been able to take the boat out to 8.5m overall (6.7m hull length), and the hardtop configuration and all-aluminium construction realises considerable gains in interior space compared to Sport RIB and Sport D-Tube models. This boat weighs in at 2,250kg dry and has a payload of 500kg as well as 250 litres of fuel.

She featured at the recent Hutchwilco New Zealand Boat Show, where she drew a lot of admiring looks, as well as considerable interest from potential customers, says Sealegs’ Global Sales and Marketing Manager Peter Small.

“This model was particularly well received. I think it benefitted from being displayed inside under lights, which highlighted its striking orange-and-black colour scheme and our attention to detail inside and out.”

This 8.5m Alloy Cabin, the ninth boat of its line to leave the factory, benefits from a high-quality fit-out that includes Ultralon U-Dek on the cockpit sole, transom and coamings, premium seats and electronics, and a glossy, black-painted interior. Rather than feeling dark and gloomy, the boat feels inviting and luxurious inside, the black paint contrasting nicely with the orange exterior and interior highlights. Of course, the model’s available in any colour combination you like.

The review vessel is fitted with Hella Marine lighting throughout: lightbars on the hardtop, Sea Hawk-XL dual-colour floodlights for the cockpit and EuroLED white/blue lights inside the hardtop. These were used to good effect at the boat show, changing from white to blue.

Hella also supplied the anchor light, navigation lights, various courtesy lights, including strip lights under the gunwales and LEDs to illuminate the cupholders. Speakers for the Fusion entertainment system are also illuminated.

This boat differs from earlier examples in that the hardtop has been widened so it feels more spacious and the windscreen mullions have been eliminated. Instead of mullions, she features a toughened glass, three-pane windscreen with the panes bonded together. Consequently, vision through the windscreen is excellent while sliding side-windows and small skylight hatches in the hardtop roof provide ventilation and three, two-speed wipers keep the windscreen clear of spray.

Although the interior has a luxurious feel, including the generous v-berths (with infill) in the forward cabin and provision for a toilet, the boat is well set up for fishing and diving. The cockpit is a decent size and the vessel’s high sides and generous freeboard mean it should be safe in sloppy conditions. Stability at rest is good, thanks in part to reverse chines and the fact that the wedge-shaped hull is widest at the waterline along the chine. The chines also provide excellent hydrodynamic stability.

What sets the 8.5 Alloy Cabin apart from earlier Sealegs models is the successful relocation of the inboard motor to the transom, leaving the cockpit clear. The upgraded 35hp four-stroke Briggs and Stratton petrol engine is housed in the transom wall with air intakes to the front and side and the exhaust and forced air ventilation outlet to the rear.

The pumps and oil reservoirs supplying the hydraulic motors in each of the three wheels are also housed behind the transom, accessible via a hatch on the starboard side. The step-through is on the port side where the transom is slightly lower. The boarding ladder is designed not only for boarding the boat from the water, but also from land. Folding to the side, the ladder is shaped to clear the rear wheel.

One house- and one start-battery are housed under the port side berth in the forward cabin.

The Sealegs experience is similar with every model, but it doesn’t really get old. It still feels slightly odd driving a boat down the beach and into the water and vice versa, but it’s highly satisfying! Engine noise is certainly less intrusive with the Briggs and Stratton tucked away inside the transom wall.

We made several entries and exits during our afternoon with 8.5m, to accommodate photographers, videographers and others, but Sealegs’ AES is well-sorted and very simple to operate. Making the transition from land to water and back again is child’s play.

AWD ensures good traction in most situations and there’s the option of engaging ‘diff lock’, which forces all the wheels to turn in unison, to overcome more challenging beach conditions. Maximum speed on land is 7.5kph – 10.1kph with diff lock engaged. A bow camera, which feeds to the Simrad MFD, keeps you appraised at all times of what’s below the front wheel.

Sealegs has put some thought into the way the controls are laid out in the 8.5m Alloy Cabin. ‘Terrestrial’ controls, levers and instruments are largely grouped together so they are easy to operate with one hand, leaving the other one safely on the wheel. Power steering is standard, turning both the front wheel and the outboard. The prominent emergency stop button, which activates a hydraulically-released mechanical brake, is on top of the dash.

The vessel’s ‘aquatic’ controls and instruments are likewise logically grouped and there’s ample space on the dash for a 12-inch Simrad MFD, Simrad VHF, Autopilot, Yamaha Command Link display, Zipwake automatic trim tab control, Fusion stereo head unit, anchor controls and various switches.

This boat is nicely set up for fishing with a practical transom-mounted bait station that includes a good-sized live bait tank and a row of rod holders (five) and knife slots. The rocket launcher across the back of the hardtop provides storage for six more rods and there are four angled through-coaming rod holders, plus cup/sinker holders that light up at night. Side pockets are easily wide enough to accommodate dive bottles and there’s a large 450-litre wet or dry locker forward of the underfloor fuel tank.

On the water, a V6 250hp Yamaha four-stroke outboard provides the motive power. In the right conditions it will propel the 8.5m Sealegs to a top speed of 39 knots and the boat cruises comfortably at 25-30 knots. The helm position is good, Hi-Tech bolster seats on Softrider pedestals providing comfort and support. Aft facing seats have storage underneath: a pull-out Dometic fridge slots in under the port seat.

Power steering and an adjustable helm position make driving the boat a pleasure. Vision ahead is excellent, thanks to the all-glass windscreen and the way the foredeck slopes down slightly, which is a bonus when operating on land as well. The hull is soft-riding, dry and nicely-responsive to helm and engine trim inputs, handling very nicely.

When left in auto mode, Zipwake trim tabs take the guesswork out of trim settings, but trim tabs were hardly needed during our review, so we switched them off for most of it. In more extreme conditions it is often better to use the tabs in manual mode.

Perhaps the most all-round Sealegs model yet, the 8.5 Alloy Cabin opens a new market sector for the company.

A smart looker that performs well, the 8.5 has the length, on-water presence and range to tackle a variety of boating tasks. Well spec’d, comfortable and nicely appointed, it’s suitable for serious fishing and diving, as well as family boating.

There’s even the option of sleeping onboard – adding a gas cannister stove or BBQ would take care of cooking duties – and the boat can also be supplied on a conventional road trailer, for even more versatility.