Coupe-style cruisers with sturdy hulls allow owners to explore both inshore and offshore. They have the versatility to sneak under those river bridges while having the stability (unlike towering flybridge models) to comfortably blast offshore.
Australian-built motor yachts have garnered a global reputation for their premium quality and design flair, something I’m often reminded of during overseas assignments. At last year’s Miami Boat Show, despite a myriad of competitiors, the Riviera stand was packed with eager viewers. Among the reasons is timeless design.
The 645 moves this paradigm forward significantly. The motivation, of course, is that this particular boat tops Riviera’s popular SUV range, so as a flagship it has to bring enhancements from its smaller siblings, such as the competent 545 I reviewed in 2019. Experience and credentials count for everything in the premium motor yacht market, something Riviera well understands: it’s been building SUVs since 2012 and has continually refined the concept, launching more than 170 yachts ranging from 39 to now 64 feet.
Substance & style
Among the 645’s many enhancements are increased deck space, a departure from pod to shaft-driven power, plus external Humphree stabilisers. Also, finishings now include improved fine detail such as trim options.
The 645’s available in two editions – the Classic and the Newport. This boat, hull #1, came with the dark Classic finish and other enhancements. This features elegant interior furnishings, a versatile foredeck entertaining space and four-stateroom accommodation.
The Newport includes a distinctive tungsten silver hardtop, a spacious foredeck sunpad, avant-garde saloon features and three-cabin accommodation with a lower-deck lounge space. Crew accommodation is an additional option with vessels headed for European markets.
Huge double cockpit
Our review boat came with the extended and hydraulic swim platform with dual door access to the first of two aft cockpits. The transom offers versatility in the form of a fishing layout with bait well or lounge seating while a step-up brings me under the shelter of the saloon hardtop where the dinette lies.
It has the lounge to port that converts to a double daybed and another wrap-around lounge on starboard with a large folding teak table. The electric sunroof and clear side windows bring light and airiness to this space. Just below, and ideally placed for serving food, is the wet bar and electric barbecue.
A step-up through the sturdy, mirror-polished stainless sliding door reveals the saloon with island galley portside and lounge-dinette opposite. It’s another step to the steering console with its three Aras black leather bucket seats. This elevated area is clearly demarcated from the composite floored galley with a bulkhead that contains the 50-inch television, plus portside bar top.
In the galley the walnut dinette table cleverly folds down into the lounge bench when socialising is the priority over food. But drinks and nibbles can be enjoyed on the island bench, allowing a dozen to crowd round it.
Sundowners and a more intimate time can be had by enjoying the drinks from the custom cocktail cabinet that this particular owner chose to fit near the steering console – the classic vintages are housed in a stylish wine cooler. For entertainment, simply click a button to elevate the 50-inch satellite television. In party mode, pump up the volume of the Fusion hifi that’s piped throughout the hull.
Perishables are easily reached in the galley’s twin refrigerated drawers and twin freezers. Other essentials include two deep sinks, a three-plate Miele electric hob and microwave convection oven – the latter two appliances requires the inverter or the 22.5 KVA generator. An improvement on some other models, I welcome the use of fiddles for holding cooking pots – fiddles on the island bench would also be my preference. Other whiteware includes a dishwasher and (downstairs) a Miele washer/dryer.
The saloon is airy thanks to vertical bulkheads, wide opening side windows and a large sunroof in the middle. Most handy is the portside deck door which slides open parallel to the saloon bulkhead, but unfortunately it’s too wide to allow me to move past it to the aft deck. But it’s ideal for quickly going forward or securing a line midships.
Given that SUVs should also be driver’s boats, the extensive navigation console is a major feature on the 645. Triple leather bucket seats house skipper, co-skipper and guest, sensibly shaded by Riviera’s signature stylish visor which ensures the Raymarine Glass Bridge screens are daylight viewable.
There are triple 24-inch screens for navigation and two others for the MAN engine controls and CZone house systems. A small but important screen is for the new Humphree stabilisers: carbon fins that protrude from the underside of the hull and can be deployed automatically or over-ridden manually. Other options include internal gyro stabilisers.
Throttles and the Twin Disc Express joystick are nearby as are the controls for the vertical trim tabs that can be auto or manual. All other systems are managed by the CZone digital bus screen and controls. Fault-finding is a major advantage with these digital bus systems – any problems show on the screen and modes are used to quickly set the inside lighting for harbour or offshore.
Traditionalists will appreciate the chrome push buttons for repetitive controls such as wipers, lights, horn and so on. Some of this is similar to other marques but what differentiates Riviera is the detailing. So there are sturdy longitudinal handrails, Sunbrella soft furnishings and strong stainless fixings on doors and cupboards. The joinery was done with absolute precision in gloss walnut. Clearly, these boats are built to last and maintain their value.
Midship owner’s suite
Down below the owner’s cabin uses the Classic layout – the full 5.8m beam of the Riviera 645 for the midships berth while the bow has the main guest cabin, with two smaller ones between them.
The owner enjoys a king-sized bed, a feature headboard and bedside tables and ample storage underneath. There is a cedar-lined hanging wardrobe and a large TV. Airflow felt good thanks to opening portholes and fixed hull windows for natural light while headroom is a generous 1.95m.
The starboard bathroom is spacious with large shower and natural light. A second door inside it accesses the utility/washroom (which can be configured as crew quarters); and behind to the engine room, via a watertight door.
The stylish guest stateroom forward includes a walk-around queen-sized bed with storage beneath and wardrobe space either side, outboard cupboards with positive locking doors (an excellent Riviera feature), an entertainment system and a private ensuite.
Sweeping hull windows are an eye-catching feature and will draw in natural light – twin overhead hatches provided fresh air and privacy when the Oceanair screens are slid across. The port cabin has twin single beds which, at the touch of a button, form a double as the inboard bed slides across. Its ensuite is the day head.
The Classic layout includes a fourth guest cabin with two single bunks, the lower being my choice as it has the window. Alternatively, the Newport layout has an atrium lounge here.
Teak decks
Teak decking is the most satisfying feeling for bare feet in hot climates, something I’m reminded of as I make my way along the wide sidedecks with the occasional hand on the tall stainless safety rail. Here, a sunken lounge, surrounded by practical locker space offers seating for 10 people, and you can stay for some time, thanks to the ice bin and stereo.
Should you choose the Newport Edition, a large sunpad is included here. The Antipodean sun may require the optional Euro Awning here, to prolong the stay. Another aid to relaxation is the substantial anchor arrangement with large Muir vertical windlass controlling a sizeable 60kg Ultra anchor via a sturdy bow roller. Lockers for fenders and warps complete this practical area, along with substantial cleating all round.
Gold Coast Seaway
The extensive console screens were a distraction at first until I realised their value by zooming-in the charting to ensure we stayed off the surrounding sandbars.
With those expensive fin stabilisers I told myself to be careful, before easing the throttles forward. This prompted a roar from the twin MANs as the bow rose slightly. Views are excellent all-round, ideal for keeping an eye on the yahoo jet-skis, but to be sure I studied our stern camera as I sped up.
Noticeable was the more stable ride provided by the Humphree fins – it was even more apparent as I banked into a turn where the hull, amazingly, stayed mostly flat. This gave me the confidence to straighten up and go flatchat, easily reaching 31 knots as the cranks spun at 2,350rpm before slowing to a comfortable cruising speed of 22 knots. This offers a decent range of about 500 miles.
Slowing to find a bay, the joystick Twin Disc smoothly took control of thrusters and gearbox to allow me to easily back into my desired spot. Like this entire Riviera 645 SUV, the transmission is smooth, refined and without blemishes.
Proven hull
The major change for this range is the first use of external stabilisers, with the owner of this boat opting for Humphree fins. These have mode settings when underway – Haul-O mode and so on. These fit to each side of the hull base and can rotate according to requirements.
Traditionally used on larger vessels, it is interesting to see this technology now being used on smaller craft, and I believe the cost is similar to installing an internal gyro in the engine room.
A six-times Riviera buyer, the new owner clearly knew what he wanted when he upgraded from his 575 SUV, having enjoyed more than 1,100 hours of extensive cruising over seven years and thousands of nautical miles. He and his wife have cruised as far north as Port Douglas and completed two trips to Tasmania, including a circumnavigation of the wild west side.
That sort of voyaging requires a sturdy hull and the 645 is based on the proven 64 Sports Motor Yacht, done in conjunction with the 4D Designs. Hull construction continues the well-proven, hand-laid laminated technique with solid GRP around keel and other key underwater areas.
Elsewhere, it’s cored laminate on decks and cabin top to maximise insulation. The structure includes watertight collision bulkheads and wide longitudinals, while the outer skin is vinylester to prevent osmosis.
The 645’s engine access is via a deck hatch or through the below-decks utility room. It’s a busy yet spacious area, dominated by the twin MAN V8s which Riviera chose because of their exceptional power-to-weight performance.
This boat easily reached 31 knots (the upgraded 1,550hp engines will deliver 34 knots). Good service access includes oilways, sea strainers and bilge/seacock access (I noted double clips on all connections). Lithium batteries (600amp/hr) for house uses have been used on this model.
Fuel is distributed to three fire retardant GRP tanks moulded into the hull, with twin wing and one forward tank that helps balance the trim.
