HMS Riant was a 40nt steel steam drifter. Originally known as Green Sea, she was built by the Coulby Brothers of Lowestoft and launched in 1920. Her dimensions were 26.3 x 4.1 x 2.8 metres. She had a single screw and one boiler and triple expansion engine.
The Riant was originally ordered by the Admiralty and intended as a Naval Drifter but was completed after the First World War. She was sold to the Fisheries Board for Scotland in 1920 and registered at Aberdeen as A.639. In 1921 she was sold to a E.W. Mutton and renamed Gladys & Violet. Her final change of hands was in 1924 when she was sold to David Main, John Ralph & D.W. McKenzie of Burghead and registered at Inverness as Riant (INS.30).
From 1932 - 1936 she conducted seasonal trawling for white fish out of Fleetwood under management of Alex Keay. On 27th November 1939, the Riant was requisitioned for war service as a minesweeper at the hire rate of £32 per month. She spent her war service employed on auxiliary patrol. She foundered on 27th January 1940 after hitting the Carraig Mhor rocks off Gigha during a storm. The Riant began leaking badly and sank soon after. The entire crew of 14 were rescued.
Items reported to the Receiver of Wreck include two soup plates and a clock. Divers identified the wreck by locating her nameplate.