Trimaran

A multihull vessel with one main hull and two smaller outrigger hulls.

The outrigger hulls, often called amas, are connected to the central hull by transverse structures known as akas or crossbeams. Their spacing gives the vessel high initial stability compared with a similar-width monohull.

Trimarans may be sailing or powered and range from folding cruising craft to high-performance racing vessels and ships. Stability, loading, wave response and capsize behaviour differ from a monohull and depend on the complete design rather than hull count alone.