Catamaran

A multihull vessel with two hulls connected by crossbeams, a bridge structure or a deck.

Catamarans may be sail- or power-driven and range from small beach craft to cruising yachts, workboats and large ferries. The hulls are usually similar, but need not be identical in every design, and accommodation or payload may be carried in the hulls and connecting structure.

Wide hull spacing can provide high initial stability and deck area, while slender hulls can reduce wave-making resistance. These are design tendencies rather than guarantees: load distribution, bridge-deck clearance, windage, capsize recovery, motion and manoeuvring characteristics differ substantially from both monohulls and between catamarans.