hullType

Hull type, often represented in documentation as hullType, is a classification of the shape and construction of a vessel's hull that influences performance, stability, and intended use. In naval architecture, hullType typically distinguishes between monohulls and multihulls. Monohulls carry their crew and cargo on a single hull and are common for yachts and many ships; multihulls such as catamarans (two hulls) and trimarans (three hulls) offer additional lateral stability and space, often with reduced motion in certain seas.

Another common distinction is displacement hulls, planing hulls, and semi-displacement hulls. Displacement hulls move through the water by pushing it aside and are energy-efficient at low to moderate speeds but have a lower top speed. Planing hulls rise onto the water surface at higher speeds for greater speed in smaller craft. Semi-displacement hulls combine features of both.

Subtypes can be further refined by hull form: full-form (soft forebody), slender or fast-displacement, wave-piercing, and stepped hulls. The chosen hullType influences stability (static and dynamic), seakeeping, load-carrying capacity, and structural requirements, as well as propulsion and maneuverability.

In practice, engineers select hullType based on intended service, required endurance, operating sea state, weight distribution, and manufacturing constraints. In modeling and simulation, hullType is often encoded as an enumerated parameter that guides hydrostatic calculations, resistance predictions, and CFD analyses.