Leonardo da Vinci’s double-hull ship concept helped protect against flooding.
The design placed an inner hull inside an outer hull, creating an additional barrier between the vessel’s interior and the surrounding water. If the exterior were damaged, the second layer could reduce the chance that water would immediately reach the ship’s compartments.
This principle is different from a design intended only to reduce drag. The main benefit of a double hull is separation and protection, although the exact performance of any vessel depends on its materials, compartments, and construction quality.
Leonardo’s drawing was an early conceptual exploration rather than a tested ship plan. Modern naval architecture later developed watertight compartments and double bottoms alongside double hulls, making damage control much more systematic than it could be in a Renaissance sketch.