How to turn the classic rib boat into a foiling one? There is a French company, SEAir, which is specialized in this type of equipment.
It is not always a question of projects born from scratch, but also of retrofit operations: the idea of the company is in fact to give everyone the opportunity to make their inflatable boat “flying”. For example, even a standard Zodiac 5.50 has been modified with two J-shaped foils, i.e. two appendages that make this inflatable boat stand up to the water.
The horizontal part, the one that gives the “upward thrust” facing the outside of the hull (contrary to what, for example, happened in old America’s Cup catamarans). The barrel of the foil slides up and down through a hole in the hull and continues inside the steering console. The adjustment of the foil from the rest position, with the tip, the horizontal part, near the hull, to the navigation one, is done by means of electric controls, as well as the angle of incidence of the foil with the water.
In foiling conditions, the keel remains about 25 cm from the surface of the water, both for the thrust of the two foils and for the fin placed at the foot end of the outboard engine. The navigation is very comfortable (you can’t feel the waves), even if the sea is wavy.
The passage of the wave becomes very soft, but above all the fuel-saving is exceptional: on average the fuel consumption (measured comparing an identical model, but not transformed) is 30% lower reaching a 50% saving in ideal conditions. The drawbacks of foils are mainly about the space they need onboard and the cost.