| 1915 | E21 | Launched |
| 1929 | Rainbow (N16) | Laid Down |
| 1929 | Rover (N62) | Laid Down |
| 1941 | Upholder (N99) | HMS Upholder torpedoes and damages the Italian merchant Dandolo 2.5 nautical miles north-west of Barone, eastern Sicily. |
| 1941 | Upright (N89) | HMS Upright fires two torpedoes at the Italian floating drydock GO 22 off Cape dell'Armi. The torpedoes miss and Upright is heavily depth charged by the escorts. |
| 1941 | Urge (N17) | In position 38`15'N 13`24'E a 2,500 ton Tanker was missed. |
| 1942 | Unbeaten (N93) | HMS Unbeaten torpedoes and damages the Italian merchant Vettor Pisani off Argostoli, Greece. |
| 1943 | Unrivalled (P45) | HMS Unrivalled sinks the Italian auxiliary minesweeper R 172/Impero with gunfire off Amantea, Italy. |
| 1945 | Sidon (P259) | Sidon was diverted to search for the crew of an American Liberator which had come down off Siagon, in conjunction with USS Submarine Hammerhead and US aircraft. After 4 days of searching she recovered 2nd Lt Stanley Reed USAAF. He had been adrift for 5 days with little food & water. He had drifted 287 miles from the ditching position. In the words of the patrol report, "The joy on his face when he saw Sidon amply repaid all the fruitless searching and false hopes we had experienced." |
| 1945 | Sea Dog (P216) | HMS Seadog sinks a Japanese sailing vessel with gunfire in the Strait of Malacca. |
