threehulled

Threehulled is an English adjective describing something that has three hulls. The more common form in technical writing is three-hulled or trimaran when referring to a vessel with three hulls. The single-word variant threehulled may appear in older texts, informal writing, or product naming.

In naval architecture, a three-hull design consists of a central hull and two smaller outriggers connected by crossbeams or trusses. This arrangement yields a wide effective beam and high initial stability while often preserving a relatively low wetted surface area. The two outer hulls can also carry masts, rigging, or equipment separate from the main hull.

Advantages include increased stability, greater deck and storage space, and reduced wave-making drag at speed, compared with a comparable monohull. Disadvantages include more complex construction and structure, higher weight and cost, and potentially more difficult maneuvering, mooring, and maintenance. In most technical contexts, the term trimaran is preferred for a three-hull vessel, but threehulled remains a valid, if uncommon, descriptor.

Modern three-hull designs appear in both sailing and powercraft, especially high-performance trimarans used in racing and some fast ferries and research platforms. The term threehulled is primarily descriptive and is less commonly used outside specific discussions or branding.