what is it? Is it a hidrofail or.....?

[tamkvaitis]

I found it in one site about multihulls. tris basicly. What do you think about it?

[tspeer]

You're looking at the stern of an ama from a Catri trimaran. The Catri has inclined dagger boards in the amas to provide vertical lift as well as side force.

The Catri is unusual in that it uses hydrofoils to reduce the displacement and wetted area, but doesn't try to fly the boat completely out of the water. So her stability comes from a combination of hydrofoil balance and buoyancy.