Leonardo da Vinci proposed a double hull to reduce damage from a breach in a ship’s outer skin.
A double-hull design places an additional layer inside the outer hull, creating a space between the two surfaces. If the external layer is damaged, the inner layer can help prevent water from reaching the vessel’s main interior spaces. The concept is an early example of compartmentalized protection in ship design.
Leonardo’s notebooks contain many studies of ships, water flow, pumps, and naval engineering. His double-hull idea was not the same as a modern cargo ship built to current maritime regulations, but it anticipated the value of separating the outside shell from the protected interior.
Modern double hulls are especially associated with oil tankers and other vessels where preventing leaks and limiting flooding are major safety concerns. Leonardo’s proposal remained a design concept rather than a widely implemented Renaissance shipbuilding system.