A Hydrofoil for the Average Sailor
The WindRider Rave is the first production hydrofoil for an everyday sailor. It's a modest sized boat made of rotomolded plastic---like a common kayak. It's a trimaran. And they say it easily goes 30mph. Cool!
Planing hydrofoils on a boat hull lift it out of the water as it goes faster and faster until the whole hull is airborne and there's very little drag left---just sails pulling the thin foils thru the water. It's a very fast way to sail! And heeling-angle can also be controlled this way---tilt various foils to various angles to keep a boat sailing more upright if you like.
Here's further indepth info on it.