Leonardo da Vinci’s double hull was a shipbuilding concept using two layers of hull structure to help protect a vessel from leaks. The arrangement placed an additional barrier inside the outer hull, making it harder for damage to reach the ship’s interior.
Leonardo studied ships, water flow, and military engineering throughout his notebooks. A double hull could be useful for a vessel operating in dangerous conditions because a puncture in the outside layer would not necessarily flood the entire interior. The idea also reflects Leonardo’s broader interest in separating spaces and strengthening structures.
This concept should not be confused with the modern double-hull tankers required for some oil transport. Modern ships use engineered compartments, advanced materials, and detailed safety standards; Leonardo’s proposal was a Renaissance design study rather than a tested industrial specification.
Leonardo’s ship ideas included other features for navigation and naval warfare, but the double hull is specifically about protection against damage and leakage. It is best understood as an early conceptual step toward layered marine construction.