Leonardo da Vinci proposed a double hull to improve a ship’s resistance to sinking.
His notebooks include ship designs with an inner and outer layer, creating a protected space between them. The basic idea is similar to later double-hull construction: if the outside shell is damaged, the inner hull can help keep water away from the main interior spaces.
Leonardo was not the first person to think about compartmentalization or reinforced vessels, and his drawing was not a complete modern naval specification. Still, the design shows his habit of treating a practical problem—water entering a ship—as a question of structure, buoyancy, and redundancy.
Modern ships use double hulls for several different purposes, including protection against collision and reducing oil spills from tankers. Leonardo’s proposal should not be described as a modern tanker design, but its central protective principle is recognizable.