HMS Otus was an O-class submarine of the Royal Navy. She was laid down by Vickers-Armstrongs of Barrow-in-Furness on 31 May 1927, launched on 31 August 1928[1] and commissioned on 5 July 1929.
Otus was first commissioned for service with the 4th Submarine Flotilla on the China Station, and when the war broke out in 1939 she was deployed with the 1st Submarine Flotilla based at Alexandria with the Mediterranean Fleet. From July to December 1941 the submarine was based at Malta from where she carried out interception patrols with the 1st Flotilla.[1]
During 1941 she carried out patrols off Azores in defence of HG convoys on passage to and from Gibraltar, and with for patrol of Oran to intercept Vichy reported to about to attempt passage to France during Operation Principal.
On 14 August 1941 she was involved in a friendly fire incident, when the submarine under the command of Lt.Cdr. M. Willmott, RN mistook her for an enemy submarine and fired several torpedoes at her, approximately 140nmi north-west of Alexandria (position 32°41'N, 27°35'E).[2]
On 3 September 1941, under command of Lt. R.M. Favell, RN, Otus unsuccessfully fired a torpedo at an unidentified enemy armed merchant cruiser of 4000 tons, approximately east of Valletta, Malta.[2]
During 1943 she was transferred to Simonstown, South Africa for purposes of anti-submarine training.[1]
During December 1944 she was nominated to be withdrawn from service. She was paid-off and transferred to Reserve status. During 1945 she was transferred to Durban, South Africa. Otus was scuttled off Durban in September 1946.[1]
The wreck was located during March 2013 approximately 8km (05miles) south-east of the Durban Harbour entrance, at an approximate depth of 100m (300feet).[3]