Motor gunboat 81 was built for the Royal Navy in 1942. It is believed to be the only gunboat in World War II restored to her original condition. These gunboats were fast with speeds up to 45 knots and were designed for the protection of shipping in UK coastal waters, particularly to guard against the threat of German E-boats, groups of which would cross over the Channel and attack merchant shipping.
In 1945 MGB 81 passed into private ownership. It was involved in a smuggling operation in 1958 and was subsequently sold for scrap, but ended up as a permanent mooring in the sailing school. In 1968 it was bought by a boat preservation trust and restored to its wartime condition.
MGB 81 is currently berthed at the Portsmouth historic dockyard.