Leonardo da Vinci proposed a double hull to reduce flooding after a ship’s hull was breached.
The concept placed an inner hull inside an outer hull, creating a protective space between them. If the outer shell were damaged, the inner barrier could help keep water away from the vessel’s main interior. Leonardo included the idea in his studies of naval engineering and ship construction.
A double hull was not a complete guarantee against sinking. Its effectiveness would depend on the strength of the partitions, the quality of construction, and the location and size of the damage. Renaissance shipbuilders also lacked modern welding and standardized watertight compartments.
The design is often compared with modern double-hull tankers and ships, but the later vessels use advanced materials and detailed compartment systems. Leonardo’s proposal is best understood as an early conceptual use of layered hull protection rather than a modern ship blueprint.