Which Leonardo da Vinci design used a double hull to improve a ship’s safety?

Leonardo da Vinci designed a double-hulled ship to improve a vessel’s safety.

A double hull places a second layer of structure around the inside of a ship’s outer hull. If the outer layer is damaged, the inner layer can help keep water away from the vessel’s main interior spaces. Leonardo explored this idea in Renaissance naval designs, showing an understanding that separated layers could provide protection against collision or attack.

His concept was not a modern oil-tanker double hull and should not be confused with a submarine. Leonardo’s design belongs to a broader group of shipbuilding and military proposals recorded in his notebooks. It was an idea for reducing the consequences of hull damage, not a complete modern naval architecture plan.

Double-hull construction became important in later shipbuilding for different practical reasons, including collision protection and pollution prevention. The basic principle remains recognizable: an outer shell can absorb damage while an inner shell preserves buoyancy and protects the cargo or crew spaces.