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. Both Allied and Axis countries made heavy use of minesweepers throughout the war.
Combatant nations quickly adapted ships to the task of minesweeping, including Australia's 35 civilian ships that became auxiliary minesweepers. Minesweeping made significant advancements during World War II. By the end of the War, naval mine technology had grown beyond the ability of minesweepers to detect and remove. The dedicated, purpose-built minesweeper first appeared during World War I with the Flower-class minesweeping sloop. These reserve Trawler Section fishermen and their trawlers were activated, supplied with mine gear, rifles, uniforms and pay as the first minesweepers. A Trawler Section of the Royal Navy Reserve became the predecessor of the mine sweeping forces with specially designed ships and equipment to follow. 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. Sir Arthur Wilson noted the real threat of the time was blockade aided by mines and not invasion. 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.