Leonardo da Vinci designed a double hull as a shipbuilding feature intended to improve safety.
A double hull places an inner hull inside an outer hull, creating a protected space between them. Leonardo’s ship drawings explored this arrangement as a way to reduce the danger of water entering the main interior after damage to the outside. The concept also reflects his broader interest in buoyancy, naval engineering, and the movement of water.
Leonardo did not create the modern regulatory double hull used on many oil tankers. His Renaissance proposal was an early design study, and it was not a standardized shipbuilding system of his time. Modern double hulls use carefully engineered compartments, materials, and structural rules.
The double hull should also be distinguished from a catamaran, which has two separate hulls joined side by side. Leonardo’s concept placed one protective hull within another rather than simply using two parallel hulls.