What type of protective vessel did Leonardo da Vinci design with a double hull to resist leaks?

Leonardo da Vinci designed a double-hulled ship, using two layers of hull structure to reduce the danger of flooding after damage. His notebooks contain several ideas for improving ships and protecting them from leaks.

A double hull creates an inner and outer barrier separated by a space. If the outer layer is breached, the inner hull can remain intact, helping the vessel stay afloat. Modern ships use double hulls especially for safety and environmental protection, although their construction and regulations differ greatly from Leonardo’s sketches.

Leonardo’s design belonged to a broader group of maritime inventions, including pumps, cranes, and mechanisms for ship construction. He understood that compartmentalization and structural redundancy could make vessels safer, even though he lacked modern materials and naval engineering methods.

The sketch should not be confused with a submarine. A double-hulled ship is a surface vessel with protective layers; the defining idea is hull separation, not underwater operation.