Minesweeper
In Great Britain, naval leaders knew before World War I that sea mines were a threat to the nation's shipping. The real threat was not invasion, but blockade aided by mines. Fishing nets pulled behind boats gave an idea on how to clear mines. The Royal Navy used fishermen and their fishing trawlers to keep the English Channel clear of mines. They were supplied with mine gear, rifles, uniforms and pay as the first minesweepers.