On July 12, 2017, SEAir launched a slightly modified Zodiac 5.50: a RIB that incorporates foils and sails over water! This is not the first powerboat sailing this way. Foils have been used for a long time, even on commercial boats for passenger transport.
By equipping a Zodiac 5.50, SEAir wants to show that it is possible to sustain a motorboat belonging to "the man in the street". Back from the first tests, Richard Forest, president of SEAir, explains the objective of this assembly and the first sensations collected during this sea trip.
Tell us about this project of a semi-rigid hydrofoil
To equip this semi-rigid, we respected a simple set of specifications. The boat must keep all its characteristics of semi-rigid. It has to be able to stow away, to be able to be coupled to a quay or a pontoon, and to be able to be taken out of the water on a trailer. We didn't want to change the functions of the boat while adding the ability to fly.
A foil is installed under the hull. It has the shape of a V and fits perfectly under the redan and the flanges. "This foil shape was an additional constraint, but it flies! The foil goes up and down in a well in the center of the hull. Its angle of attack is adjustable.
The engine is standard. We voluntarily chose a market engine (editor's note: a 115 hp Yamaha). We just opted for an ultra-long shaft bolted in the classic way on the transom. On this engine, we have added load-bearing planes.
How did the first tests go?
The first tests took place at the beginning on a completely flat river. The first flight was done without any problem. Then we came to Lorient harbor to sail with a small chop. There, the boat behaved perfectly without even hitting. To have a point of comparison, we have a second identical RIB, but without the foils. It was starting to shake the crew, while the prototype was sailing comfortably. Finally we went out to sea. There was 1 m of swell. In this situation, the 2 boats behaved identically. We had to slow down. But that's normal with this sea on a 5.50 m boat!
We took measurements during our first outing yesterday, but we have not yet analysed the results. By sailing the 2 boats simultaneously, we will be able to compare speeds and consumptions with precision. But the first results are very encouraging: less consumption, more rpm
See you in the future?
This Zodiac 5.50 is a prototype, but we are currently working on the industrialized manufacture of foils. So that it is a robot that does the draping in the mold. This will be the next step with new tests at the end of the summer.
How do you imagine the first customers?
The first sales will probably be to racing teams who are aware of foils. But sailing schools that sail a lot could also be interested. We think that at the beginning, we will make refits of existing boats, adaptations of our system.
But already some major boatyards have approached us to integrate this system into their series production. I can't give you a brand name, but why not a motorboat specially designed for foiling in 2018?
