Motor Gun Boat (MGB) was a Royal Navy term for a small military vessel of the Second World War. Such boats were physically similar to Motor Torpedo Boats, (MTBs) but equipped with a mix of guns instead of torpedoes. Their small size and high speed made them difficult targets for E-boats or torpedo bombers, but they were particularly vulnerable to mines and heavy weather. The large number of guns meant the crew was relatively large, numbering as high as thirty men.