A naval mine is a self-contained explosive device placed in water to damage or destroy surface ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of, or contact with, any vessel or a particular vessel type, akin to anti-infantry or anti-vehicle mines. Naval mines can be used offensively, to hamper enemy shipping movements or lock vessels into a harbour; or defensively, to protect friendly vessels and create "safe" zones. Mines allow the minelaying force commander to concentrate warships or defensive assets in mine-free areas giving the adversary three choices: undertake an expensive and time-consuming minesweeping effort, accept the casualties of challenging the minefield, or use the unmined waters where the greatest concentration of enemy firepower will be encountered.
The Royal Danish Navy is the sea-based branch of the Danish Defence force. The RDN is mainly responsible for maritime defence and maintaining the sovereignty of Danish territorial waters. Other tasks include surveillance, search and rescue, icebreaking, oil spill recovery and prevention as well as contributions to international tasks and forces.
The Finnish Navy is one of the branches of the Finnish Defence Forces. The navy employs 2,300 people and about 4,300 conscripts are trained each year. Finnish Navy vessels are given the ship prefix "FNS", short for "Finnish Navy ship", but this is not used in Finnish language contexts. The Finnish Navy also includes coastal forces and coastal artillery.
HMS Ivanhoe was an I-class destroyer built for the Royal Navy in the mid-1930s. During the Spanish Civil War of 1936–1939, the ship enforced the arms blockade imposed by Britain and France on both sides as part of the Mediterranean Fleet. Before the start of World War II, the ship was modified so that she could be used to lay mines by removing some of her armament. Ivanhoe was transferred to Western Approaches Command shortly after the war began and helped to sink one German submarine in October 1939. She was converted to a minelayer while undergoing a refit in November–December and laid minefields in German coastal waters as well as anti-submarine minefields off the British coast until she was reconverted back to her destroyer configuration in February 1940. Ivanhoe reverted to her minelaying role during the Norwegian Campaign in April 1940 and then laid a number of minefields off the Dutch coast during the Battle of the Netherlands in May. The ship participated in the Dunkirk evacuation until she was badly damaged by German aircraft on 1 June. On her first minelaying mission after her repairs were completed, she struck a German mine and had to be scuttled on 1 September 1940 during the Texel Disaster.
A minelayer is any warship, submarine or military aircraft deploying explosive mines. Since World War I the term "minelayer" refers specifically to a naval ship used for deploying naval mines. "Mine planting" was the term for installing controlled mines at predetermined positions in connection with coastal fortifications or harbor approaches that would be detonated by shore control when a ship was fixed as being within the mine's effective range.
The Romanian Naval Forces is the principal naval branch of the Romanian Armed Forces and operates in the Black Sea and on the Danube. It traces its history back to 1860.
The British L-class submarine was originally planned under the emergency war programme as an improved version of the British E-class submarine. The scale of change allowed the L class to become a separate class.
The Abdiel class were a class of six fast minelayers commissioned into the Royal Navy and active during the Second World War. They were also known as the Manxman class and as "mine-laying cruisers". These ships were armed with a wide variety of defensive weapons from 0.5-inch (13 mm) machine guns to the 4-inch (100 mm) main armament. They were also equipped with a wide array of radars, along with their normal complement of mines. They were easily mistaken for destroyers. Half the class was lost through enemy action during the Second World War; the others saw post-war service, and the last example was scrapped in the early 1970s.
HNoMS Tyr was a Gor-class Rendel gunboat built for the Royal Norwegian Navy at Karljohansverns Verft Naval Yard in Horten. She was laid down in 1884 and launched in 1887 with build number 67. Tyr was one of a class of two gunboats - the other ship in her class being HNoMS Gor. Gor and Tyr can be seen as improved Vale-class gunboats, of 290 tons instead of the 250 tons standard for that class.
The North Sea Mine Barrage, also known as the Northern Barrage, was a large minefield laid easterly from the Orkney Islands to Norway by the United States Navy during World War I. The objective was to inhibit the movement of U-boats from bases in Germany to the Atlantic shipping lanes bringing supplies to the British Isles. Rear Admiral Lewis Clinton-Baker, commanding the Royal Navy minelaying force at the time, described the barrage as the "biggest mine planting stunt in the world's history." Larger fields with greater numbers of mines were laid during World War II.
HMS Adventure, pennant number M23, was an Adventure-class minelaying cruiser of the Royal Navy built in the 1920s that saw service during the Second World War. Her commander between 1928 and 1929 was the future First Sea Lord John H. D. Cunningham. Laid down at Devonport in November 1922 and launched in June 1924, Adventure was the first vessel built for service as a minelayer; she was also the first warship to use diesel engines, which were used for cruising. Adventure first joined the Atlantic Fleet, then was transferred to the China Station in 1935. In World War II, the ship was damaged in 1941 and 1944, and was converted to a landing craft repair in 1944. In 1945 Adventure was reduced to reserve and in 1947 she was sold and broken up for scrap.
The Type 082 class minesweeper is a Chinese People's Liberation Army Navy (PLAN) ship class. It is also known as Wosao class in the west, but the Chinese media has translated the name as Wusao, short for armed mine sweeping boat. As with most mine countermeasure vessels in PLAN, all Type 082 ships are also equipped with mine laying rails and thus are also deployed as minelayers.
The Northern Barrage was the name given to minefields laid by the British during World War II to restrict German access to the Atlantic Ocean. The barrage stretched from the Orkney to the Faroe Islands and on toward Iceland. Mines were also laid in the Denmark Strait, north of Iceland.
The Kamishima class minelayer was a class of minelayers of the Imperial Japanese Navy (IJN), serving during and after World War II. Nine vessels were planned under the Maru Sen Programme; however only one vessel was completed by the end of war.
HMS Manxman (M70) was an Abdiel-class minelayer of the Royal Navy. The ship is named for an inhabitant of the Isle of Man. It served in the Mediterranean during World War II, and entered the Reserve Fleet following the end of the war.
Louhi was a Finnish Navy minelayer. The ship was originally constructed for the Imperial Russian Navy but was taken over by the Finns during the Russian Civil War. She had originally been named Voin, but was renamed as M1 in Finnish service. In 1936 she was given the more personal name Louhi, following the procedure of all other major ships in the Finnish navy.
The Albona class were mine warfare ships used by the Regia Marina and Royal Yugoslav Navy (KM). Fourteen ships were originally laid down between 1917 and 1918 for the Austro-Hungarian Navy as the MT.130 class. However, the end of World War I and the dissolution of Austria-Hungary left them incomplete until 1920, when three ships were finished for the Regia Marina. An additional five ships were completed for the KM in 1931 as the Malinska class or Marjan class.
HMS Telemachus was a R-class destroyer of the British Royal Navy that took part in the First World War. She was built in 1916–1917 by the Scottish shipbuilder John Brown at their Clydebank shipyard. Telemachus was modified to serve as a minelayer, laying minefields in the German Bight and English Channel to restrict the operation of German submarines. The ship survived the war and was sold for scrap in 1927.
JDSSōya(MMC-951) was an minelayer of Japan Maritime Self-Defense Force (JMSDF) in the early 1970s.
People's Liberation Army Navy 
