Trimaran

A trimaran is a three-hulled craft with a central main hull and two outrigger floats, or amas, that supply righting moment at very low weight. The form is the basis of the fastest offshore racing yachts, the Ultim and Multi70 classes that hold the round-the-world and ocean records, because the leeward float carries the rig’s heeling force while the windward float lifts clear. Cruising trimarans trade some of that speed for accommodation and the ability to dry out upright.