Thousands of smaller warships and auxiliaries served in the Kriegsmarine, including minelayers, minesweepers, mine transports, netlayers, floating AA and torpedo batteries, command ships, decoy ships (small merchantmen with hidden weaponry), gunboats, monitors, escorts, patrol boats, sub-chasers, landing craft, landing support ships, training ships, test ships, torpedo recovery boats, dispatch boats, aviso, fishery protection ships, survey ships, harbor defense boats, target ships and their radio control vessels, motor explosive boats, weather ships, tankers, colliers, tenders, supply ships, tugs, barges, icebreakers, hospital and accommodation ships, floating cranes and docks, and many others. The Kriegsmarine employed hundreds of auxiliary Vorpostenboote during the war, mostly civilian ships that were drafted and fitted with military equipment, for use in coastal operations.