Recently, I found myself standing at a campsite in a place called Wilsons Promontory (it’s actually a peninsula). I heard a dull rumble, a thrumming of engines, and turned to see an almighty sight. A large boat, flanked by a small cadre of spotters, was driving down the road?! And there were two more behind it!
I’d never seen anything like this in my life. An amphibious boat with wheels that could self-launch on the beach! I quickly puzzled out that this craft had a hydraulic system for raising and lowering its wheels. This allowed the wheels to be deployed for entering and exiting the water and raised to reduce drag when at sea. Genius!
I surmised that this technology was too cool and too useful to be a one-off build, and I was right. Once I got home, I dived into the research and got my answer. What I was looking at was a boat equipped with “Sealegs,” a unique amphibious technology straight out of New Zealand.
On Land, On Sea
As the company tells it, the concept for Sealegs started as a napkin sketch in 2001 and eventually became a production reality in 2004. Since then, the company has expanded to offer a range of amphibious watercraft equipped with wheels. Sealegs also sells its amphibious drive systems such that they can be integrated to designs from other manufacturers.
Throw the Sealegs gear on a boat, and you have an amphibious platform that can be operated with a minimum of supporting infrastructure. There’s no need for boat ramps, jetties, or other structures. The boat can simply deploy its wheels and drive on to land—and vice versa. This also makes launching the boat far easier and more practical, reducing the number of crew to do so safely.
The basic concept is simple. The boats are fitted with three wheels—two at the back, one at the front. These wheels are mounted on hydraulic rams so they can be extended and retracted as desired. Each wheel is fitted with a hydraulic motor, giving the craft all-wheel drive. If you haven’t heard of a hydraulic motor, it’s quite simple. It’s a motor that turns when you pump it full of hydraulic fluid under pressure.
Of course, to run the motors, you need a source of hydraulic pressure. This is typically achieved with a small auxiliary engine running a hydraulic pump. The engine can be set up to run off the same fuel tank that supplies the boat’s sea engines. If you have a smaller boat equipped with, say, Sealegs System 70 setup, it comes with a 35 hp Briggs & Stratton petrol engine. If you have a larger craft, you might be running the Sealegs System 100 setup with a larger 97 hp Kubota diesel.
Depending on the exact setup chosen, it’s possible for a duly equipped craft to achieve speeds of up to 7 mph on land. Maximum torque is as high as 7,744 foot-pounds with a System 100 setup; it’s enough to climb up to a 15-degree grade in the right configuration. The largest Sealegs setup is suitable for vessels with a gross weight of up to 16,000 lbs.
Alternatively, Sealegs has also developed an electric system, too, for its small Electric E4 craft. This replaces the hydraulic wheel motors with brushless electric hub motors good for up to 6 mph. They’re paired with a 7 kWh lithium-ion battery, with a total run time of 1.5 hours. That’s enough for up to 20 launch and retrieve operations on a single charge, or around 1.5 hours of driving around on land.
Sealegs has sold amphibious vessels to users all over the world. They’re particularly popular with first responders, who get great utility out of the self-launching capability.
Down At The Prom
The boats I saw down at Wilsons Prom are some of the biggest vessels equipped with Sealegs gear. They were designed and built specifically for tourism operator Pennicott Wilderness Journeys by Sealegs, Naiad Design, and Naiad’s Australian builder, Kirby Marine. The resulting craft – the Naiad 11.5 m Tourist Sealegs – carries 30 passengers plus two crew. Each boat is equipped with twin Yamaha 350-horsepower outboards for propulsion on the water. The boats can easily reach 38 knots with the engines at half-load, with typical cruise speed stated as 25 knots.
Despite their size, the craft will do 5.6 mph on land. That’s more than enough for launch and recovery operations and getting the boats off the beach. Indeed, as I saw during my stay on the Prom, the boats are driven quite a ways off the beach, through the campsite, and to a dedicated parking area of their own.
A tender was put out to multiple boat operators to run the tourist boating operation at Wilsons Prom, and Pennicott came out ahead thanks to the Sealegs technology. The ability of the boats to self-launch and recover meant that the wilderness region could remain unspoiled. There was no need to build a jetty, dock, or ramp that would otherwise clutter the pristine coastline.
These boats are very cool. They look totally badass when they’re crawling on land, and they’re pretty swift on water, too. If I ever get a boat, I’ll dearly want it to have the cool wheels so I could just drive it in and out of the water at will. If you’ve experienced the hell of launching and recovering a boat by yourself, you’ll know exactly what I’m talking about.
Image credits: Lewin Day, Sealegs, PennicottJourneys via YouTube screenshot
I love this design. For first responders as you said, or any kind of research where you want to access remote islands with no infrastructure. Such an elegant solution to a problem. Hell, I know hunters and fishers that would LOVE this for getting small boats to difficult-to-access lakes and rivers all over Canada.
In France there is a chap making a boat-car called the Tringa, which is fully licensed for the road — although it only goes 16 kph on land. Sold mainly in Brittany where there are lots of coves with slipways but not much space in marinas… Sells about 10 a year.
Take a look on mussels harvesting vehicles of Brittany:
https://www.youtube.com/watch?v=N2hKqCkJ75g
Those are basicly fishing boats on wheels, that seem to be bespoke builds.
How well do these things do as landing craft?
This is so cool. I literally got rid of my boat due to the hassle of launching it, and then of course, getting it back on the trailer as I am admittedly, quite a novice… This seems to be the best way. Thanks for sharing this way cool
A smaller, more complex variant :
https://www.iguana-yachts.com/
Fun fact: I saw ‘Gremlins’ for the first time at the Tidal River movie “theatre”. And it was a proper outdoor cinema back in the early 80s.
Also it was the only place I’ve ever seen a person (my brother) run over by a wombat.
Wombats drive?
Who knew?
Do they drive Wartburgs?
What? How does that even happen? They’re like a ~2’ tall hamster sort of thing.
In the 70s, ChicagoLand area Brookfield Zoo had a wombat exhibit where I, sucking my fingers burnt by the injection-molded vending-machine wombat (slow learner), would proudly deposit my saved allowance/paper route money in the Save the Wombats box each summer
Maybe it was a Combat Wombat!
They are a very dense ‘hamster’ since they can weigh over 30 kg (66 lbs). He was attempting to catch it but, in the melee, proceeded to get stomped on by 20 something kilograms of very determined to be elsewhere wombat.
Seriously cool! Genius simplicity. Very Boatopian.
We used to camp there for family holidays at Easter each year when I was a kid – back then when it was permitted, people used to just launch small fishing boats directly off the beach by backing their trailer directly into the sea with a 4WD. The beach there is pretty firm sand, so people hardly ever got stuck, but if I remember right the Parks Service had a tractor there that could pull people out of the sand.
It seemed much more Wild West back then than it is now – the garbage truck was a rusty ute with the doors removed so the driver could hop in and out easily to empty the bins, and they had only a basic first aid clinic where a random doctor once had to take a time out from his family holiday to sew up a gash in my scalp after an accident.
Random fact: in the picture showing the whole beach with the creek (Tidal River) in the foreground, you can see the water in the creek looks dark brown – it’s stained from all the Melaleuca trees along the river, known as Tea Trees as a result. Swim in the creek and all the hair on your body gets stained dark as a result, so you come out of the water looking like a Sasquatch.
Melaleuca oil is quite pungent: did the creek have that odor?
I can’t actually remember – although I think the scent of tea tree oil is basically just a background scent in most parts of Australia!
While the price doesn’t bother me one bit (those are for business applications and will pay for themselves if they are really needed, they are not that much more outrageously priced than a set of Mattracks and those sell quite well to this day), I am a bit skeptical about the “complex hydraulics & salt water” combo.
This should be very simple hydraulics, and hydraulics probably mix better with salt water than any other propulsion scheme you could come up with. I certainly prefer hydraulic drive to the electric option.
We had a tree pruning tower, a three wheel thing with a boom you would stand in with two of the wheels driven by hydraulic motors. Steering was by controlling the motors independently just like on a caterpillar tractor or combine.
Anyway, the hydraulic motors and pump were the most reliable parts of the contraption. The pump was of course the same as the motors. Even the saws, one circular and one chain, were hydraulic. I recall the pressure accumulator was a bit finicky and the engine was controlled by the accumulator in sort of an off and on arrangement which wore engines out every year. But that was all because we were turning the motors off and on or adjusting the boom constantly. The pressure surges were insane.
This application wouldn’t have any of those problems.
Oh man, utes, Margot Robbie, and now wheelie boats. Why don’t I live in Australia?
Spiders and deadly deadly snakes?
The dire state of housing affordability?
The inevitable conclusion that your life has entered a state of managed decline from which it will not return?
So, basically – every other US state, but with Margot Robbie, Utes and now wheelie boats ?
My understanding is that, compared to Canada and especially Australia, real estate in the US is downright cheap.
New Yorker here, so – choking on my coffee as we speak.
https://www.numbeo.com/property-investment/rankings_by_country.jsp
….I guess averages really skew it?
… yeah no. Expensive AF. Heavy AF. Which means slow AF.
You need to try driving a 16-20′ performance hull with single high perf outboard, and try balancing on the pad built into the hull. Then you will understand what a fun boat is. 🙂
It’s a 30 person tour boat. It’s supposed to be slow.
Nobody is suggesting you put three big agricultural flotation tires on your offshore racing boat.
That’s a pretty big boat…
2010 Sealegs 6.1m RIB | 20ft $44K

No thanks
It seem like one of those ‘If you have to ask…’ things. Although that applies to most marine-ware.
B.O.A.T.
Bring Out Another Thousand.
Boats are holes in the water into which one throws large amounts of money. The only comparable motive hobbies for expense are horses and aircraft, imo.
And miss all the fun of dealing with a slimy, too-steep ramp and all of the fun it entails?
Boating smells like gasoline, suntan lotion, dead fish, and hot vinyl all mixed together.
Is this proof that Torch is wrong in stating that an amphibious car is both a compromised car and a compromised boat? This thing boats better than most boats out there…
But it hardly cars. Top speed is lacking quite a lot. For their Dhingy it’s top speed is 5 MPH, with a 1 hour run time, netting a 5 mile range out of a 3kWh battery.
Expensive and heavy is not better than most boats.
You think this isn’t a compromised car? Have you seen a car before?
Amphibious cars are a dead end. Amphibious airplanes are where it’s at. Actually, flying boats, not those float planes although those are nice too.
Actually, I would love a DUKW as an RV, but that’s not a car.
You ever notice that no one ever talks about amphibious boats? Why is that?
I’ll probably end up getting the Dhingy variant in the next few years. However I’d prefer an all aluminum option in the same length or shorter.
Imagine a properly small 2-3 place dhingy! You could probably get it to 6-8ft
A lot of places public beach regulations allow you to launch from the beach but not drive on it with a car. Which usually means you’re launching small boats that can be pushed there. Or boats that are beached from the water.
I could see this as a way around the regulation allowing the tour company to operate from the beach but not have to pay for any property on the water or rights to build a launch or dock. Clever.
Being a National Park, there’s no way the tour company would be allowed to build any infrastructure on the beach, and there’s nowhere suitable to build a dock either, even if that would be permitted. It’s such a rugged and undeveloped landscape that the current campsite there at Tidal River was used as a base for training army commando units during WWII.
It’s cool, but the actual use case seems extremely narrow and most boat owners/operators would be better served by a trailer, which would be much cheaper in most cases.
Except you don’t have to reverse your tow vehicle down a boat ramp to launch – then leave someone on the boat to move it out while you take your tow vehicle and trailer into the lot and find a double-space to pull thru to park.
You don’t really need a boat ramp at all – which means no boat-ramp lines on busy weekends.
You can just unhitch in the parking lot, lock your tow vehicle – then drive the boat over the beach into the water.
Seems a no-brainer.
I don’t know. I am sure that it works but I just think that you are adding a lot of complexity and maintenance. Boats work in a comparatively harsh environment and now you are adding hydraulic pistons and lines, extra engines/motors and electronic controls systems. Further your boat is going to be heavier both because of the weight of the system and the need to have a structure strong enough to carry the boats entire loaded weight at the three axle points. All this costs money and boat trailers comparatively are pretty cheap.
Yeah, you don’t need a boat ramp, but most people do so they’re common.
I’ve launched a boat off a ramp with a mate a few times and it always sucks big time
Virtually everything you said is wrong. Let’s take ‘you won’t need a boat ramp’. Well, that’s only true if the beach you launch from is made of the right type of sand, and has a slope less than a certain amount. If you launch on a river or lake that doesn’t have a sandy shore, you’re still going to need a boat ramp.
Next – leaving someone on the boat when you launch. I normally launch solo. I just tie up my boat at the dock at the ramp and then move my truck into the dedicated truck/trailer parking spots at the boat ramp. I normally can launch or recover just as fast (and many times faster) as a group because I have the whole system down. Most of the time groups spend at the ramp is them trying to load and unload the boat either at the dock or on the ramp, either way blocks the use of the ramp for everyone else. I put everything I need in my boat at home.
Next – no boat-ramp lanes. You think they will let you just drive your boat anywhere on the shore to launch it? Those will be either protected wetlands, or a beach full of people.
Now on to things you didn’t mention. You have big wheels and tires attached to your boat. They’re in the way when the boat in in the water, plus they added unnecessary weight that will add to fuel costs in the boat all the time it’s running. The added cost will be more than a boat trailer costs. If the tire goes flat, you’re looking at a lot more damage to your boat because you don’t have a trailer frame between the boat and the road.
All in all, this is a solution for a very limited subset of boating – a commercial application where the boat never leaves the side of the water, and has a dedicated space to store the boat and enter/exit the water.
I guess you’re right in the sense that if you’re keeping your boat at your house, you can’t drive it all the way to the launch like this. But if you live beachside or within a mile or so, I think this’d rock.
Ok, The word for taking your boat off a trailer and into the water is “launch” what is the One word for putting the boat back on the trailer and driving home? “recover”? It is called d”recovery” in the article. that seems clunky.
I thought “boat launch” was the place you launched a boat. Google Maps shows several boat launches near me. Google Maps shows no boat recoveries near me. This has me somewhat concerned.
it’s like a pool in The Sims with the ladder removed
This is extremely cool. Although it’s immediately got me thinking about a non-powered version, basically removing the trailer part of normal boat ownership. All you would need would be a winch on your tow rig.
You’d need a ton of suspension, which means even more weight and more importantly more bulk.
Maybe for the big twin engine fuckers in the article, but the little dingy would work. You would manually fold the wheels down so you lose the extra engine/battery and hydraulic system
Try folding a wheel/tire inflated with air under the water while sitting in your boat. Probably not as easy as you think.
True, but without the driving motors you could probably just run the actuator of the regular 12-volt battery
I’ve seen it done before, but not for high speed travel.
First, a trailer is probably cheaper than this set-up. Next you aren’t carrying around unneeded weight while boating, which burns fuel faster. Also, you have some protection from road damage with the trailer frame. Have a tire go flat and you might scrape your boat on the road. Lastly, the hydraulics involved in raising and lowering the tires are an added expanse and complexity, plus there’s the weight of the pump and fluid (although I’ll throw in that I actually already have 3 hydraulic systems on my boat, but none large enough to raise the boat wheels, it’s probably actually the fluid capacity that adds the most weight – the 3 systems are the power steering, the power trim for the sterndrive and the power trim tabs.)