| 1940 | Tetrarch (N77) | HMS Tetrarch torpedoes and sinks the Italian merchant Snia Amba off Benghazi, Libya. |
| 1941 | P511 | USS R-3 was transferred to the Royal Navy at New London. She joined 7th Flotilla at Holy Loch for anti-submarine warfare training in January 1942. |
| 1941 | Unbroken (P42) | Launched |
| 1941 | P511 | Completed |
| 1941 | P551 | Decommissioned from USN and simultaneously transferred to United Kingdom where she was renamed HMS P551 |
| 1942 | X3 | Sank while on exercise in Loch Striven due to a leaking engine valve. All crew escaped by using Davis Submerged Escape Apparatus. |
| 1944 | Terrapin (P323) | HMS Terrapin torpedoes and sinks the Japanese minesweeper W5 in Malacca Strait. |
| 1944 | Volatile (P96) | Completed |
| 1960 | Odin (N84) | Launched |
