Monohull

A vessel whose main buoyant structure consists of a single hull.

The term distinguishes conventional single-hulled vessels from multihulls such as catamarans and trimarans. A monohull may be sailing or powered and can have many different underwater forms, including displacement, semi-displacement and planing hulls.

Its stability and motion depend on hull shape, loading, ballast and design rather than on hull count alone. Sailing monohulls commonly heel under sail, whereas a multihull obtains much of its initial stability from the spacing between its hulls.