What type of vehicle did Leonardo da Vinci design with two hulls to reduce the danger of sinking?

Leonardo da Vinci designed a double-hulled ship intended to reduce the danger of sinking.

The concept used two parallel hulls rather than one single body. A divided structure could provide greater stability and might allow a vessel to remain afloat if one side were damaged. Leonardo explored this arrangement as part of his broader studies of shipbuilding, naval engineering, and the behavior of water.

A double hull is not the same as simply making a ship wider. It creates separate buoyant compartments, although the usefulness of the design depends on construction quality and how water is prevented from spreading between spaces. Modern ships sometimes use double hulls for safety and environmental protection, but their engineering is much more advanced.

Leonardo’s drawing should be treated as a historical concept, not proof that he built a successful double-hulled vessel. His notebooks contain many practical studies alongside speculative designs. The proposal illustrates his habit of applying structural reasoning to problems of stability, damage, and buoyancy.