A ship is scuttled when its crew deliberately sinks it, typically by deliberately opening holes in its hull.
Scuttling may be performed to dispose of an abandoned, old, or captured vessel; to prevent the vessel from becoming a navigation hazard; as an act of self-destruction to prevent the ship from being captured by an enemy force (or, in the case of a vessel engaged in illegal activities, by the authorities); as a blockship to restrict navigation through a channel or within a harbor; to provide an artificial reef for divers and marine life; or to alter the flow of rivers.
The Skuldelev ships, five Viking ships, were sunk to prevent attacks from the sea on the Danish city of Roskilde. The scuttling blocked a major waterway, redirecting ships to a smaller one that required considerable local knowledge.
In 2012, a cog preserved from the keel up to the decks in the silt was discovered alongside two smaller vessels in the river IJssel in the city of Kampen, in the Netherlands. The ship, dating from the early 15th century, was suspected to have been deliberately sunk into the river to influence its current.
The Spanish conquistador Hernán Cortés, who led the first expedition that resulted in the fall of the Aztec Empire, ordered his men to strip and scuttle his fleet to prevent the secretly planned return to Cuba by those loyal to Cuban Governor Diego Velázquez de Cuéllar. Their success would have halted his inland march and conquest of the Aztec Empire.
HMS Sapphire was a 32-gun, fifth-rate sailing frigate of the Royal Navy in Newfoundland Colony to protect the English migratory fishery. The vessel was trapped in Bay Bulls harbour by four French naval vessels led by Jacques-François de Brouillan. To avoid its capture, the English scuttled the vessel on 11 September 1696.
HMS Endeavour was Captain James Cook's ship upon which he discovered Australia. After being sold into private hands, she was finally scuttled in a blockade of Narragansett Bay, Rhode Island in 1778.
The British sank one ship on 10 October 1781 to prevent it from being captured by the French fleet.