Glossary · Keels, foils & rudders
U-foil
Also called: Foil en U, U-shaped foil
A foil whose tip turns back up, forming a U, to keep lift as it rises out of the water.
On a U-foil, the wing tip turns up towards the surface. As the boat rises, part of it stays immersed and keeps lifting, which smooths the flight. The shape is mainly used on multihulls.