Leonardo da Vinci proposed a double hull to make ships safer if one outer hull was damaged.
The concept places an additional layer of structure inside or alongside the exterior hull, creating separation between the sea and the vessel’s interior. That space can help prevent immediate flooding after a breach in the outer skin.
Leonardo’s maritime studies included ship designs and practical ideas for improving naval construction. His double-hull concept resembles a principle later used in modern ships, especially tankers, where separated hulls provide additional protection.
A Leonardo sketch is not the same as a modern regulated double-hull vessel. Contemporary designs depend on detailed structural calculations, watertight compartments, materials standards, and international safety rules.