Events
On This Day - December 21
| 1896 | 1886 - 1912: Pactolus | Launched |
| 1929 | Odin (N84) | Completed |
| 1934 | Sealion (N72) | Completed |
| 1936 | Thetis (N25) | Laid Down |
| 1936 | Thunderbolt (N25) | Laid Down |
| 1942 | Safari (P211) | HMS Safari sinks the Italian auxiliary minesweeper Rosina S. about 5 nautical miles south of Hammamet, Tunisa. |
| 1942 | Sportsman (P229) | Completed |
| 1943 | Sportsman (P229) | HMS Sportsman attacks and damages the Greek sailing vessel Spiridon with gunfire south of Lemnos island. |
| 1944 | L26 | HMS L-26 paid off Halifax NS |
| 1944 | Trenchant (P331) | HMS Trenchant sinks two Japanese landing craft with gunfire off the eastern coast of Sumatra. |
| 1944 | Spearhead (P263) | Completed |
| 1961 | Opossum (S19) | Laid Down |
| 1982 | Torbay (S90) | Laid Down |
