Leonardo da Vinci proposed a double hull to help a damaged vessel stay afloat.
A double hull places a second watertight layer inside or around a ship’s outer hull. If the outer skin is breached, the inner layer can prevent water from immediately flooding the vessel. Leonardo explored this principle in his notebooks while studying naval engineering and methods of improving ship safety.
The idea belongs to a broader group of Leonardo’s maritime designs, including pumps, paddle mechanisms, and specialized boats. His notes often combine practical engineering with speculative concepts, so not every drawing was intended as a complete construction plan.
Double-hull construction became especially important in modern shipbuilding and tanker safety. It should not be confused with a double-ended ship, which has a bow and stern arranged for operation in both directions, or with watertight compartments, which divide the interior into separate sections.