Fin5, the small electric outboard that works without a propeller
The last boat show of 2022 took place in Paris, from 3 to 11 December , in the "indoor port" set up at Porte de Versailles, where 650 boats were put on display and 1300 brands represented. Among the many, a small start-up based in Normandy played an important role: it is called FinX, it is not yet known beyond the French borders, but it seems to have what it takes to play an important role in the transformation process that the world of pleasure boating is experiencing, increasingly oriented towards environmentally friendly productions.
Working on the front of electric propulsion and safety , the French technicians have created a small outboard motor with zero emissions: called Fin5, it is able to move small boats (rowboats, tenders, dinghies) by renouncing the thrust of a propeller. The new propulsion system is based on a ducted membrane, which provides thrust. In more detail, the effect of the movement in a fluid of a deformable elastic membrane placed between two flanges is exploited. The waves thus created propagate from the entrance to the exit and give the thrust necessary for navigation.
Operation is powered by a 48 V battery and the power developed – according to the information provided by the designers – is 2 kW, which the French company optimistically equates to about 5 horsepower of a traditional heat engine. As for autonomy, again according to the manufacturer, sailing at a speed of 2.7 knots the Fin5 can operate for 8 hours, which can be reduced to one hour if pushed to the limit. It is worth remembering, however, that these are theoretical data, all to be verified, given that no one, not even the most qualified specialized magazines, has so far had the opportunity to test the revolutionary outboard without propeller and without emissions.
Perhaps the most important value, beyond the reduction of harmful emissions, is safety: the engine without a propeller, in fact, eliminates the risk of accidents for both humans (swimmers) and marine animals. “You can swim and touch the working membrane without any risk,” assures Harold Guillemin, founder of FinX. Furthermore, the risk of mechanical failures is extremely limited, while the absence of rotating parts prevents wear and helps eliminate the risk of collisions on particularly shallow waters. The same goes for the accidental winding of submerged ropes: a canceled risk.
Other considerable advantages are represented by the low weight (18 kg) and the possibility of recharging using a solar panel. It is worth remembering, however, that it is necessary to have a battery with sufficient charge, because it is not integrated into the standard equipment of the engine. On the other hand, a small computer that optimizes performance is supplied with the outboard. All for the price of 3,200 euros.
The inspiration for this decidedly revolutionary solution came from dolphins, cetaceans that move their tail fins with great amplitude at low frequencies. However, the effectiveness of the system in turning or in reverse remains to be verified (presumably the engine will have to be rotated by 180°, directing the propulsion system towards the bow).
According to the FinX technicians, this first small revolutionary outboard is dedicated not only to small boats suitable for short navigations along the coast but "also to sailboats up to 3 tons". Also in this case, assessments appear to be optimistic, as are those relating to the design of a 100 kW propellerless electric motor, which according to the French company "will express a power equivalent to that of a 150 hp motor".