Leonardo da Vinci proposed a double hull to reduce flooding in ships.
Leonardo’s naval studies included the idea of constructing ships with two layers of hull material. The inner and outer layers could create a protective space, so damage to the outside would not immediately expose the vessel’s main interior to water. This is the basic principle behind a double hull.
A double hull is not itself a complete ship design and does not make a vessel unsinkable. It adds protection against certain impacts, but flooding can still occur through major damage or openings. Leonardo’s proposal belongs to a broader group of studies on shipbuilding, hydraulic engineering, and military technology.
Modern tankers and some other vessels use double-hull construction for safety and pollution prevention. International rules introduced after major tanker accidents made double hulls an important feature of many oil tankers. Leonardo’s Renaissance proposal therefore resembles a later established engineering principle, although its historical context and construction methods were very different.