The earliest known usage of the
naval mine dates to the
Ming dynasty. Dedicated minesweepers, however, only appeared many centuries later during the
Crimean War, when they were deployed by the British. The Crimean War minesweepers were rowboats trailing
grapnels to snag mines. Minesweeping technology picked up in the
Russo-Japanese War, using aging
torpedo boats as minesweepers. In Britain, naval leaders recognized before the outbreak of
World War I that the development of sea mines was a threat to the nation's shipping and began efforts to counter the threat.
Sir Arthur Wilson noted the real threat of the time was a blockade aided by mines and not an invasion. The function of the fishing fleet's trawlers with their trawl gear was recognized as having a natural connection with mine clearance and, among other things,
trawlers were used to keep the
English Channel clear of mines. A Trawler Section of the
Royal Navy Reserve became the predecessor of the mine sweeping forces with specially designed ships and equipment to follow. These reserve Trawler Section fishermen and their trawlers were activated, supplied with mine gear, rifles, and uniforms, and paid as the first minesweepers. The dedicated, purpose-built minesweeper first appeared during
World War I with the
Flower-class minesweeping sloop. By the end of the war, however, naval mine technology had grown beyond the ability of minesweepers to detect and remove mines. Minesweeping made significant advancements during
World War II. Combatant nations quickly adapted ships to the task of minesweeping, including Australia's 35 civilian ships that became
auxiliary minesweepers. Both Allied and Axis countries made heavy use of minesweepers throughout the war. Historian Gordon Williamson wrote that "Germany's minesweepers alone formed a massive proportion of its total strength, and are very much the unsung heroes of the
Kriegsmarine." Naval mines remained a threat even after the war ended, and minesweeping crews were still active after
VJ Day. After the Second World War, Allied countries worked on new classes of minesweepers ranging from 120-ton designs for clearing
estuaries to 735-ton oceangoing vessels. The
United States Navy even used specialized
mechanized landing craft to sweep shallow harbors in and around
North Korea. , the
U.S. Navy had four minesweepers deployed to the Persian Gulf to address regional instabilities. The Royal Navy also had four minesweepers stationed in the Persian Gulf as part of the
9th Mine Counter-Measures Squadron until early 2026. ==Operation and requirements==