With the advent of electric vehicles and, for that matter and more recently; electric boats and outboard motors, the term hybrid has very much entered mainstream, day to day conversations. Conventional dictionary definitions describe the term as something that is a mixture of two very different things, or a thing made by combining two different elements. These definitions ‘somewhat’ apply to the new Sealegs 3.8 TE RIB (Rigid hull Inflatable Boat). I say somewhat, simply because the 3.8 TE (Tender Electric) embraces more than two elements.
From the get-go, for over twenty years, Sealegs boats were – and still are hybrids in the traditional two elements sense. That is, they are craft that perform on water and, being amphibious boats with wheels, have the capability to travel over land. But the 3.8 TE combines yet another element – being driven on land powered by battery electric motors while utilising a traditional 40 hp Yamaha petrol outboard out at sea. Sealegs’ products have been innovative from the beginning and the 3.8 TE takes their pioneering approach to yet another level. True Kiwi Ingenuity at its best! But why a small (for Sealegs) hybrid tender? To answer this question and to find out how this new model performs out on the water and over land, I spent time with Jake Olliff, Sealegs’ electric design engineer, tasked with developing this model.
The idea for the 3.8 TE came about approximately two and a half years ago and was driven primarily by market demand from a select segment of the boat building industry. A well-known Aussie manufacturer of luxury power boats, in the 20 to 23 metre (65’ – 75’) range, wanted an eco-friendly tender which would fit neatly into their on-board tender storage garages or be easily lifted on deck by davit from the three strong lifting points. A further consideration was the fact that Sealegs appreciated that the 6 to 8 metres length RIB market was already crowded and that by being the first to develop an inimitable 3.8 model, they could stay ahead of their competitors.
The 3.8 TE further expands the Sealegs range – now spanning ten models from 3.8M to 12M. The 3.8 TE is a complete system redesign starting from a blank slate. Sealegs built on their experience with their electric land driven 7.5 metre model, which utilises powerful, high-torque hub-mounted brushless electric motors to effortlessly and quietly, drive this electric amphibious craft out of the water and up beaches and through difficult terrain. Being their first foray into electric propelled wheels, the drive technology of the above-mentioned 7.5 Electric has been well proven since its introduction 6 years ago. But the 3.8 improves on this electric drive development even further. Although confident that a tender such as the 3.8 would be popular, Sealegs adopted a rather clever marketing approach to gauge the degree of market demand before committing significant resource to the project.
Prior to building a prototype they advertised their intent to develop the 3.8M on their website, requesting that interested customers place a significant deposit, thus demonstrating their serious interest while providing Sealegs with ‘seed capital’ to justify proceeding with the project. They set their benchmark at 15 deposits, reasoning that this was a go/no-go line and, that once there, would feel confident that they were on the right track. Currently they have secured orders (with deposits) for 23 boats and have a fully working prototype that continues to undergo significant stress testing across a range of environments.
It was this “all but finished” craft that we used for our land and sea trials on a pleasant, mid-November spring day at Gulf Harbour, north of Auckland. As Jake and I unloaded the 3.8 TE from its trailer and readied it for its sea (and land) trials, I recalled the first time I saw a Sealegs boat. Almost twenty years ago, during my time with Maxwell Winches and while exhibiting at the Dubai Boat Show, a young chap by the name of David McKee-Wright, a Sealegs co-founder, had brought the first of their, then strange, ‘new craft’ to the show, hoping to attract the interest of affluent Gulf State customers. As an intrigued fellow Kiwi exhibitor, we struck up a conversation during which I was not only impressed with this revolutionary amphibious concept, but also the enthusiasm David had for his product.
I couldn’t help thinking to myself, “These guys are onto something”. Two decades on, Sealegs craft are no longer considered strange and even though bystanders still stop and stare as they witness a Sealegs boat trundle down a beach, the craft are now somewhat ubiquitous, especially in New Zealand. But time to see if the 3.8 TE delivers. The first thing I should mention is that although Jake brought the boat up to Gulf Harbour on a trailer, likely only about 10% of customers are going to trailer this craft. After all, it is called a ‘tender’. And, by definition, a tender is essentially a smaller craft that runs back and forth from a larger boat, typically ferrying passengers to and fro from ship to shore.
Once off the trailer – easy when you can simply drive it off and onto the boat ramp parking lot – Jake ran me through the ‘on land’ operating system. However, before discussing the controls, what is immediately obvious is that there are three retractable wheels. Two at the stern and one in the bow. The stern wheel drives contain 2.2 kw electric motors, used to propel the boat while on land. These motors are enclosed in completely sealed units, containing a viscous thermal and water ingress resistant gel and collectively produce about 6 Hp. May sound small, but being electric are very efficient and generate impressively powerful torque. The tyres were chosen for their knobbly, high grip tread and fit smoothly into the wheel wells forward and aft. The bow wheel is used only to steer the boat and is currently unpowered, but this may change in the future to fall in line with most of the larger Sealegs boats which are generally AWD.
Power is supplied by a 3kWh battery pack, installed under the bow seat, to assist with overall stability of the craft. The electric motors enable the ‘vehicle’ to travel at a top speed of approximately 10 kmph (6 mph), depending on terrain and incline. It is recommended that the maximum ‘up’ incline is 14 degrees (25% grade) and ‘down’ incline is 11 degrees (20% grade) – a little steeper than the average boat ramp. Average run time on land, again depending on terrain, is 45 minutes with the battery charge percentage being displayed on the Simrad chart plotter unit, which also shows popup notifications at key percentages. Fully recharging the batteries takes 3 hours utilising a 24-volt ‘off boat’ charger unit. Some regenerative charging comes from the outboard, but this is quite minimal.
I stress at this stage that this very close to ‘production ready’ model is still a work in progress prototype and although very near to being churned out in volume, there are still some final, minor tweaks and developments being incorporated into the ultimate production units. On first glance, the controls look a wee bit Intimidating. But remember, this is a land and sea vessel, so in effect, two sets of controls. However, once you wrap your head around the fact that while on land you will be using one set of controls, and at sea, another set, it is all quite straight forward – the on-water controls being much the same as any helm station controlled, outboard vessel.
Nevertheless, since we are yet to get the 3.8 TE in the water, let’s look at those land controls first. Immediately to the right of the steering wheel there is a black ‘joystick’. This is used for forward and reverse manoeuvres while on land. Push it up (towards the bow) and you go forward. The further you push it the faster you go. Push it down (towards the stern) and you are into reverse, then ditto above. The next thing to note is the eight-button panel directly above the joystick. On land steering on the production units will be provided by the helm steering wheel. The pre-production prototype we were on utilised an ‘interim” steering solution – with the lower, left two buttons, with arrows pointing port and starboard, being currently used for steering – moving the front wheel left or right as you press either the port or starboard button respectively. However, this will not be an issue on production models, the 3.8 TE will be steered by means of the steering wheel, once Sealegs are confident that the steering wheel system is working reliably. The ‘steering’ buttons are only a temporary modification, fitted so that the engineers (mainly Jake) could get the boat out on the water quickly for testing and reliability of the rest of the systems. No customer craft will be sold with this button steering. Whew!
But what about the other six buttons on this current ‘steering’ panel?
Moving clockwise from top left; Navigation and Anchor light Control, Courtesy Light Control, All Wheels Up Activation Control, Pin Code Unlock Button, Amphibious System Enable Control, All Wheels Down Control. And we can now ignore the left/right steering buttons. That’s about it for the ‘land based’ controls, except for that big red panic button. It is there for one very good reason. If everything starts turning to custard while on land, bang down on that control and everything comes to a stop! Think of it like a hand brake on a car.
So, land operation briefing complete, it’s time to head for the water. Although I got the chance to drive it into and out of the water at the beach later in the day, I was quite happy for Jake to do the initial demonstration drive down the slippery (tide out), sharply inclined boat ramp. One thing for sure, you can’t help smiling as you slowly trundle towards the water, perched on your currently landlocked steed, soon about to transform and become a sea horse in the water. If you’ve never experienced an amphibious craft, it is hard to describe the buzz. Really fun comes to mind, though!
Once in the water and tying alongside the boat ramp jetty to take some photos, Jake began to explain to me how to operate the RIB on the water. This part was more familiar as the controls are the same as for any small to medium, helm station-controlled vessel. Steering wheel where it should be while the driver is seated to starboard on the two-person helm seat, the forward/aft throttle control lever to starboard and the on/off engine key on the lower port corner of the helm console below the Yamaha CL5 digital readout display unit. The futuristic steering wheel, which can be tilted down to fit into the tender garage more easily, also houses several control buttons (see image above). Rounding off the displays you will find the centrally mounted, easy to read Simrad NSX 3009 chart plotter and depth sounder which also displays all operationally relevant information for the electric amphibious system. A mini aquatic Starship Enterprise!
But back tracking for a moment. One thing Jake did stress as we entered the water, is the importance of getting the outboard motor started and the propeller shaft down as you get into deep enough water while at the same time start retracting the wheels; controlled by the clearly marked buttons on the port side of the steering wheel. All sounds a bit complicated, but it really isn’t. An analogy that comes to mind is learning how to first drive a manual transmission car compared to an automatic. Seemed formidable at the time, but after a few days of driving a ‘stick shift’ it all became second nature. Same with the Sealegs. By the end of the day, wheels up/down co-ordinating with outboard up/down, all became familiar.
I realised as we got ready to head out to sea, that once again I was doing a boat review that was two tests in one (Refer November/December 2023 Issue) as the amphibian hybrid duality became clearly apparent. Fully briefed by Jake, I took the helm as we rounded the Gulf Harbour breakwater to put this new Sealegs tender through its paces. A slight to moderate sea and a southerly breeze provided conditions that could typically be encountered by future 3.8 TE owners as they use the craft to ferry their guests and crews to shore and back from the mother ship anchored offshore in a sheltered bay.
First impressions are the most noteworthy and one of the first things that struck me was how roomy this little RIB is. Ideal for two to four people, it is however rated for a maximum payload of 425kg (937lbs), roughly translating to four passengers plus the driver. With only four people on board there is ample room for the driver and one passenger on the aft helm seat, with the second passenger being accommodated on the ‘jump seat’ to port of the helm console and the fourth person sitting in the roomy bow seat. There is storage under the aft bench seat for the outboard fuel tank and other small accessory equipment. Under the wide forward seat, the custom anchor locker can be found, while the “still top secret” battery pack and other equipment is housed below this in a sealed, but accessible bow compartment. Before hitting the throttle for the first time, I asked Jake how aggressive I could be during the sea trials. He quite confidently said; “Go for it”. So, I did! Bracing myself at the wheel I reached for the throttle control lever, which I must confess I found to be positioned a bit ergonomically awkward when engaging the lever in the fully forward throttle position. Mentioning this to Jake, he agreed and advised that they were working on how to better position the control lever on the helm console, while still being able to accommodate the plethora of other equipment, wiring cables and controls also housed within the cabinet. Knowing how Sealegs constantly strive for perfection, I am confident that this little niggle will be sorted out on their production units. Speaking of the helm station, the windscreen on all production units will also be able to be tilted (like the steering wheel) to offer a lower profile for on-board tender garage storage in the mother ship.
Given the green light, the fun began. Knowing full well that the typical owner of this tender would be unlikely to hammer it through seas as I was about to, I really wanted to see what this radical little craft could do. The 40 Hp Yamaha is a more than adequate power unit and on a calm water run we topped out at around 20 knots with two of us on board. Trimming the boat on the plane is done solely by adjusting the motor position but Jake hinted at the fact that Sealegs is developing an automatic trim, which will make life that much simpler. The Seastar hydraulic steering is positive and the boat planes well with 2 – 3 people on board. Interestingly, the only hydraulics on this boat is for steering the outboard. Suffice it to say, the 3.8 TE didn’t disappoint. Whether through tight turns, thumping head on into waves or trying to make her ass slide out of control through sharp ‘S’ manoeuvres, the worst I could come up with is that she can be a little wet when hammering into waves as the wind blows back the sea spray and her stern can be a little skittish in tight (Ron’s race mode) performances. The ‘wetness’ can be forgiven.
This boat isn’t designed for the type of stuff I was putting her through. She’s meant to ferry folks back and forth to shore. However, I wondered aloud with Jake about the slightly sloppy stern. Jake explained that there were several challenges in relation to the aluminium hull design and although they had started by using a ‘bog standard’ 4 metre hull, several criteria had to be considered: not least of which being the added weight of the wheels and 40 Hp Yamaha outboard on the stern. In addition, the batteries to power the wheels also had to be housed somewhere, ending up as it turned out, in the forepeak of the hull below the custom anchor locker. Sealegs is continuing to tweak the hull which, being aluminium, it is simple to modify, unlike a composite molded hull, and they are confident that the production models will overcome the tendency for stern slide.
All that aside, Jake and I had a ton of fun out on the water, and I was mightily impressed with the way the 3.8 TE performed at sea. But after spending time zapping around the bay, I was keen to drive this creature up and down on land. Fortunately, it was low tide and the small beach to the west of the boat ramp provided the ideal spot to take the boat ashore. Remembering Jake’s tutorial, I concentrated on the console in front of me as well as watching where I was going as we neared shore, while ascertaining that we were approaching shallow enough water to engage the wheels, I stared down at all the controls – some on the console and some on the steering wheel. I’ve got this! Once fully up on the beach, time to get off the boat and stretch our legs. Retract all three wheels and the tender sits comfortably level on the sand allowing passengers to easily exit the boat and stay dry ready for a stroll up the beach to that fashionable restaurant where they intend to while away the afternoon eating and drinking, before returning to the luxury mother ship as the sun sets at the end of a beautiful evening. James Bond, eat your heart out!
But time to wrap things up. Back on board and now quite familiar with the controls, power turned on, I engage the wheels to the fully down position, back up a little bit to get away from the rocks at the top of the beach (joystick pulled slowly aft) and then slowly forward on the joystick, we accelerate a bit more and head for the water. Once I feel the boat start to float, I simply reverse all the procedures I employed driving ashore and, hey presto, outboard started and tilted down, wheels up and locked throttle forward and we are on our way back to the boat ramp. As we near the ramp I remember: “Oh yeah, we don’t need to tie alongside the boat ramp jetty so we can get off and head for the parking lot to get the boat trailer; we just have to drive the boat up the ramp”. Gotta love it!
Before summarising our day out, I realise that I had tended to overlook many of the other fine touches that this ‘beyond state of the art’ craft, features. First and foremost, the aesthetics. The inflatable tubes with their distinctive two-tone grey/white colour, delineated with a bright orange diagonal stripe, immediately catch your eye. Plus, little things like the retractable cleats and the faux teak, anti-slip deck treads over the rear wheel arches and bow platform. But check out the specifications chart below and their website for all the other good stuff.
This is the complete amphibious package hitting the bull’s eye for the market it is intended. But it does, as one would expect with a top quality, state of the art product, not come cheap. The introductory price topping out at NZD $175,000.00 as tested.
- LENGTH OVERALL (Wheels Up) 3.9M
- HULL LENGTH (Wheels Down) 3.8M
- HEIGHT 1.35M (Wheels Down) 0.95M (Wheels Up)
- BEAM 1.91M
- CAPACITY 5 Persons
- WEIGHT OF CRAFT (No Fuel) 550kg
- MAX PAYLOAD (Including Passengers) 425kg (937lbs)
- RECOMMENDED OUTBOARD 1x 40HP (30 kW)
- FUEL CAPACITY Petrol 25L Tote tank (under seat)
- TOP SPEED (Land) 7.5kph (5mph)
- ON-LAND POWER Electric Drive – 3kWh Battery Pack
- BRAKES Dynamic regen braking with automatic mechanical park brake
- STEERING Seastar with tilt hem and Sealegs EPS
- SEATING Bow, console and stern seating
- STORAGE Bow and stern seat storage lockers, wireless phone charger pocket
- TYRES 8”x 10” all terrain tyres
- TUBE 4 chamber, Hypalon tubes.
- LIGHTING Bow-mounted LED marine headlight (land use only),
- LED navigation lights
- DECK Anti-slip deck tread
- RUN TIME (Land) 45 minutes
- MAXIMUM INCLINE (Land) 11 Degrees (20% grade). Avoid driving across a transverse incline.
- PRICED FROM NZD $175,000.00