Floodability is a characteristic of the construction of a ship

Ship

Since the end of the age of sail a ship has been any large buoyant marine vessel. Ships are generally distinguished from boats based on size and cargo or passenger capacity. Ships are used on lakes, seas, and rivers for a variety of activities, such as the transport of people or goods, fishing,...

 to resist flooding.

Floodability is achieved by dividing the volume of the hull

Hull (watercraft)

A hull is the watertight body of a ship or boat. Above the hull is the superstructure and/or deckhouse, where present. The line where the hull meets the water surface is called the waterline.The structure of the hull varies depending on the vessel type...

 into watertight compartments with deck

Deck (ship)

A deck is a permanent covering over a compartment or a hull of a ship. On a boat or ship, the primary deck is the horizontal structure which forms the 'roof' for the hull, which both strengthens the hull and serves as the primary working surface...

s and bulkhead

Bulkhead (partition)

A bulkhead is an upright wall within the hull of a ship or within the fuselage of an airplane. Other kinds of partition elements within a ship are decks and deckheads.-Etymology:...

s (which also increase the strength of ships

Strength of ships

The strength of ships is a topic of key interest to naval architects and shipbuilders. Ships which are built too strong are heavy, slow, and cost extra money to build and operate since they weigh more, whilst ships which are built too weakly suffer from minor hull damage and in some extreme cases...

), use of double bottom

Double bottom

A double bottom is a ship hull design and construction method where the bottom of the ship has two complete layers of watertight hull surface: one outer layer forming the normal hull of the ship, and a second inner hull which is somewhat higher in the ship, perhaps a few feet, which forms a...

, and by other means.

Watertight bulkhead compartments were written of by the Song Dynasty

Song Dynasty

The Song Dynasty was a ruling dynasty in China between 960 and 1279; it succeeded the Five Dynasties and Ten Kingdoms Period, and was followed by the Yuan Dynasty. It was the first government in world history to issue banknotes or paper money, and the first Chinese government to establish a...

 Chinese author Zhu Yu

Zhu Yu (author)

Zhu Yu was an author of the Chinese Song Dynasty . He retired in Huang Gang of the Hubei province, bought a country house and named it "Pingzhou". He called himself "Expert Vegetable Grower of Pingzhou ". Between 1111 and 1117 AD, Zhu Yu wrote the book Pingzhou Ketan , published in 1119 AD...

, in his book Pingzhou Table Talks of 1119 AD (written from 1111 to 1117 AD). Watertight compartments were frequently implemented in Asian ships, and had been implemented in the warships of Kubla Khan.Watertight compartments in AsiaKabla Khan's warships having watertight compartmentsWatertight compartments used by Zheng He Chinese sea-going junk

Junk (ship)

A junk is an ancient Chinese sailing vessel design still in use today. Junks were developed during the Han Dynasty and were used as sea-going vessels as early as the 2nd century AD. They evolved in the later dynasties, and were used throughout Asia for extensive ocean voyages...

s often had 14 crosswalls, some of which could be flooded to increase stability or for the carriage of liquids.

Alexei Krylov

Alexei Krylov

Aleksey Nikolaevich Krylov was a Russian naval engineer, applied mathematician and memoirist.-Biography:Alexei Nikolaevich Krylov was born on August 3 O.S., 1863 to the family of an Army Artillery officer in a village Akhmatovo near town Alatyr of the Simbirsk Gubernia in Russia...

 and Stepan Makarov

Stepan Makarov

Stepan Osipovich Makarov was a Ukrainian - born Russian vice-admiral, a highly accomplished and decorated commander of the Imperial Russian Navy, an oceanographer, awarded by the Russian Academy of Sciences, and author of several books. Makarov also designed a small number of ships...

worked extensively on ship floodability in the early 20th century.