thumb|The wreck of SS Reginald, a blockship sunk in Weddell Bay in the Orkney Islands, [[Scotland in 1915]] thumb|Cruiser Spanish cruiser Reina Mercedes|Reina Mercedes, sunk by its own crew in the [[Spanish-American War, blocking access to the port of Santiago de Cuba.]]
thumb|The wreck of SS Reginald, a blockship sunk in Weddell Bay in the Orkney Islands, [[Scotland in 1915]] thumb|Cruiser Spanish cruiser Reina Mercedes|Reina Mercedes, sunk by its own crew in the [[Spanish-American War, blocking access to the port of Santiago de Cuba.]]
A blockship is a ship deliberately sunk to prevent a river, channel, or canal from being used as a waterway. It may either be sunk by a navy defending the waterway to prevent the ingress of attacking enemy forces, as in the case of at Portland Harbour in 1914; or it may be brought by enemy raiders and used to prevent the waterway from being used by the defending forces, as in the case of the three old cruisers , and scuttled during the Zeebrugge raid in 1918 to prevent the port from being used by the German navy.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).