Ship floodability

Floodability is a characteristic of the construction of a ship to resist flooding.

Floodability is reduced by dividing the volume of the hull into watertight compartments with decks and bulkheads (which also increase the strength of ships), use of double bottom, and by other means. If a ship's hull is divided into watertight compartments, any flooding resulting from a breach of the hull can be contained in the compartments where the flooding occurs. As long as the flooding is localised, this can allow a ship to retain sufficient buoyancy to remain afloat.

The Song Dynasty Chinese author Zhu Yu wrote of watertight compartments in his book, Pingzhou Table Talks, written from AD 1111 to 1117 and published in 1119. Watertight compartments were frequently implemented in Asian ships, and had been implemented in the warships of Kubla Khan. Chinese seagoing junks often had 14 crosswalls, some of which could be flooded to increase stability or for the carriage of liquids.

Alexei Krylov and Stepan Makarov worked extensively on ship floodability in the early 20th century.