The R boats (Räumboote in German) were a group of small naval vessels, built as minesweepers but used for several purposes during the Second World War. A total of 424 boats were built for the Kriegsmarine before and during World War II. The German Navy used them in every theatre including the Baltic, Mediterranean and the Black Sea. These boats were used for convoy escort, coastal patrol, minesweeping, minelaying and air-sea rescue.