Hulls

Hulls are the watertight bodies of ships and boats, forming the main structural element that encloses the crew, cargo, and equipment. The hull provides buoyancy and houses ballast and compartments, while its shape and construction determine stability, seaworthiness, and performance. Hulls are commonly described as monohulls or multihulls, with variations in form and purpose reflecting design goals such as speed, load capacity, and maneuverability.

Common hull forms include displacement hulls, which move through the water by pushing a large volume aside and are efficient at lower speeds; planing hulls, which ride on top of the water at higher speeds; and semi-displacement hulls, which blend characteristics of both. Multihulls such as catamarans and trimarans offer wide platforms and increased initial stability, but their hydrodynamic behavior and interior layouts differ from traditional single-hull designs.

Construction and materials have evolved significantly. Traditional wooden hulls were built from planks over frames, while iron or steel hulls dominated large ships in the 19th and 20th centuries. Modern vessels more commonly use aluminum, fiberglass-reinforced plastics, and composite materials, often with internal watertight bulkheads and stiffened frames to improve strength, durability, and safety. Design considerations include weight distribution, center of gravity, hull integrity, and corrosion resistance.

Historically, hull design has driven naval architecture and commercial shipping, from early dugout canoes and clinker-built boats to the carvel method and later steel-hulled ocean-going ships. Hydrodynamics and material technology continue to refine hull efficiency, stability, and environmental impact.

In geometry and computing, a hull refers to the convex hull of a set of points—the smallest convex shape that contains all the points. Algorithms such as Graham scan and Quickhull compute convex hulls, with applications in computer graphics, GIS, and pattern recognition.