The Sealegs concept has been going for over five years now, just to confound the early doubters who pooh-poohed the combination of a RIB with its own carriage wheels.

The intervening years have seen the Sealegs not just prove its worth, but also provide positive feedback on the longevity and reliability of the land legs. The quest for amphibious vehicles has been around since the days of the Vikings, when they used to portage their longboats overland on rollers to save a long passage around a peninsular. There are many instances of these regular portages in Scotland. Military amphibious vehicles have also been part of the defence inventory from the 1939–45 conflict when they played a vital role in various invasions around the world, including, of course, D-Day.

There is less need in civilian life, but convenience is certainly provided by the simplicity of launching, recovery, beaching and storing, especially for those with waterside properties and their own access to the water. Even if you don’t have the luxury of a boathouse on the shore and you use a park-and-launch facility, imagine the simplicity, not to mention the safety, of not having to hitch up a trailer and run it into the water – then the same again on your return. Just start the land gear motor and drive off into or out of the water. That is precisely how the Sealegs came to be designed – a couple of wealthy New Zealanders decided they wanted a boat that they could do just that with, so they designed and perfected the Sealegs system.

The new 7.1 m version provides greater deck space and seakeeping to give a wonderfully stable ride and the ability to deal with bigger sea conditions more comfortably by dint of her longer waterline length. It is amazing how much more volume an extra metre of length provides, with the increase in beam and freeboard that comes with it. Don’t be misled into thinking that this is just a stretched version of the 6.1 m – it isn’t; the 7.1 m has been designed from scratch for her length, using the same saltwater corrosion-resistant aluminium, 5083 shate. This is the same material, only not as thick as the plate, used in shipbuilding – such as with fast ferries and warships.

This particular boat is the last of what they call their ‘light’ build. In future, each Sealegs is to be built to a commercial standard of 600 hours per year for 10 years. That kind of usage would see even a heavy leisure-user through for life. The hull is left bare, as aluminium is self-protecting, with its own coating of oxide, and does not require antifouling. The remainder of the aluminium construction is powder coated, and customers can specify their own colour; white is the default colour. The aluminium structure makes for a very strong, stiff boat that is inherently lightweight. The inflatable collar is made from Hypalon 828 to complement the rugged build and is fitted so that the last metre or so sits on the water at rest, in conventional RIB format. If you took the wheels off, you would have a pretty conventional utility RIB made from long-lasting materials and built like a warship, literally.

When I first saw the Sealegs she was sat proudly in the middle of the boat park in Salcombe, gaining admiring glances from passers-by and the other boaters. We were awaiting our turn to use the slipway while the other people reversed their trailers down the ramp, floated their boats off and then came back to park their cars and trailers. Our turn came round and Nick just started the inboard motor which powers the fluid drive wheels, set the hand throttle to provide adequate revs and then pressed the joystick forward. The boat gently trundled forward, down the slipway and into the water. At this point the outboard was trimmed down and started. The driven wheels continued to push the boat forward until she floated, at which point the outboard was set in motion and the wheels lifted clear of the water on their hydraulic rams. It is a simple and elegant procedure which wasn’t lost on those still juggling trailers and vehicles and boats afloat. That is the crux of the Sealegs on land: it is a simple, safe, self-contained and self-propelled answer to launching and recovery. Playing with the trailer is a major source of stress for many boating families. The Sealegs provides an easy method of loading the kit, and for people to board before launching. The boat can safely be lowered onto the ground, with the wheels acting as chocks to prevent the boat falling sideways, removing the danger of having children around while reversing trailers, or fingers next to trailer winches.

Out on the water the wheels create no drag once they are fully raised. There is the extra weight of the undercarriage and inboard motor, but this is offset against the lighter mass of the aluminium hull and deck structures. Overall, the Sealegs is very close in ‘on-the-water’ weight to other similar-size RIBs. The hull is an unfussed design with short strakes at the stern only. Other than that, the hull is clean, with a 21-degree deadrise at the transom and a short delta pad for stability on the plane. These short strakes are enough to give stern lift and grip in turns, and the lack of forward strakes doesn’t hamper the boat getting on the plane. The fast response from the well-proven E-TEC motor pops her up very easily and then presses on to the top speed of 38.3 knots achieved on the day.

The Sealegs is a stable boat that is quite capable of running in a swell without throwing everyone on board around. When making turns in the swell you do need to take a wider berth, due to the rounded bow section slapping if banked onto a swell. This is just down to driving the boat within her comfort zone – the boat would take all manner of abuse; it is those perched within that won’t appreciate it. Taking the swell on the head, she surprised with her ability to run fast and comfortably – just tweaking the throttle on the crests, she ran flat and landed softly, the hull having sufficient shape to part the water progressively. Running down the waves showed no hint of wanting to bow-steer either, the curved rake of the bow maintaining a steady course and the big front wheel giving some protection to the collar around the bow. This is a secondary function of the leg – they do provide a substantial bump protection on each corner of the triangle. The legs being so substantial that even a very heavy impact would do no damage, they are strong enough to land an aeroplane with.

The seating layout is very simple and eminently practical. The auxiliary fuel tank forms an aft bench with roll-back support that hinges fore or aft so the seat can be used as an aft-facing observation seat for waterskiing. The helm seat also features the hinging backrest with the standing leaning-post position – my favoured one. The helm is functional and the console is just wide enough for two. The controls are laid out separately to avoid confusion. With just five minutes instruction I grasped the order of doing things; perfecting that into a seamless operation requires a little bit of practice, but after a couple of launchings and landings you can do it with your eyes shut.

The air-cooled land motor is switched on using a separate switch to provide live feed, then a starter button fires it up. The throttle lever is situated on the port side of the console and is set to provide enough revs to keep the pump hydraulic primed. The actual land speed is controlled by using the joystick: the further forward you press it the faster the wheels drive, to a maximum of 6 mph, with directional control provided by the main hydraulic steering at the wheel. This does mean the front wheel moves when you are steering the boat, but it doesn’t detract. The outboard controls are the main controls on the console and feature standard-layout wheel and throttle with electronic gauges. There is sufficient surface area to mount additional electronics. The main fuel tank is built into the hull, and the slightly larger auxiliary tank forms the base of the aft seating. It sits in a cradle and doesn’t upset the balance as it is only the equivalent of one big man. The entire deck is self-draining overside, and there is also a high-capacity bilge pump.

Driving the boat, once you get used to the slightly different view of having the landing gear in your line of sight, is no different to other utility RIBs; the handling and performance aspects of the RIB shouldn’t worry you at all. Substantiation of this is the fact that a dozen have been ordered for use by the rescue services in Malaysia and India between them. The ability to cross large tracts of sand, shingle, stones or even small rocks, albeit at low speed, is a unique feature that frees a crew up from the constraints of spits or bars across the mouth of a river at low water, for instance.

For the leisure-user, the ability to simply motor up onto the beach provides a totally new concept in beach picnicking. The need for a tender is negated, neither is there the need to beach the boat to unload and then anchor her off in water deep enough to stay afloat as the tide drops. Simply drive the boat, on its wheels, onto the beach. The legs can be lowered to allow easy disembarkation and unloading of the picnic. The convenience cannot be overlooked. Likewise when it comes to boat storage at home, on the seafront or in a park-and-launch facility: the self-contained unit is so much easier to deal with. There is a road trailer available which the boat simply drives itself onto, and is then lowered onto the cradle. Most buyers, though, have waterside properties with their own facilities, and this is where the Sealegs really comes into its own. As the boats are seen more and more, people are realising the benefits, but they do come at a price. There are two engines to pay for: the outboard and the inboard Honda V-twin to drive the hydraulics. Considering the package and the freedom it provides, it is well priced. I think the whole concept is excellent.

Simon Everett