Leonardo da Vinci proposed a double hull to help ships survive damage.
A double-hull arrangement places an additional layer inside the outer hull, leaving a space between them. If the outer layer is breached, the inner layer can help keep water from reaching the vessel’s compartments. Leonardo included this protective idea among his naval and hydraulic studies.
The proposal reflects a practical understanding of buoyancy and ship safety. It was not a complete modern shipbuilding specification, and Leonardo did not create the standardized compartment systems used on later vessels.
Double hulls are now associated especially with oil tankers, where the second barrier helps reduce pollution after a collision or grounding. Leonardo’s Renaissance concept was broader: it treated the layered hull as protection against flooding and structural damage.