Events
On This Day - December 31
| 1912 | Nautilus (N 1) | Launched |
| 1934 | Shark (N 54) | Completed |
| 1939 | Undine (N 48) | HMS Undine departed Blyth for her 4th war patrol. She was ordered to patrol in the Heligoland Bight. |
| 1940 | Sea Dog (P 216) | Laid Down |
| 1940 | Sibyl (P 217) | Laid Down |
| 1942 | P311 (Tutankhamen) | HMS P311, only unnamed T-class boat, was due to have been named Tutenkhamen. Fitted to carry human torpedoes (Chariots). Lost while engaged in Operation Principal, a chariot attack on Italian cruisers at La Maddalena. Left Scotland in November 1942 with sister-boats Thunderbolt and Trooper after addition of human torpedo deck-mounted watertight containers direct for Malta. From there, sailed with Chariots for Operation Principle. Last signal on 31st December. Probably sunk by Italian mines in the approaches to Maddalena. Lost with all hands |
| 1942 | Unrivalled (P 45) | HMS Unrivalled torpedoes and sinks the Italian merchant Maddalena south-east of Mehedia, Tunisia. |
| 1942 | Truculent (P 315) | Completed |
| 1942 | Trump (P 333) | Laid Down |
| 1942 | Ultor (P 53) | Completed |
| 1944 | Shakespeare (P 221) | HMS Shakespeare torpedoes and sinks the Japanese merchant cargo ship Unryu Maru east of Port Blair, Andaman Islands. |
| 1944 | Trenchant (P 331) | HMS Trenchant sinks two Japanese sailing vessels with gunfire in the Malacca Strait. |
| 1959 | Sealion (S 07) | Launched |
| 1974 | HMCS Rainbow | HMCS Rainbow paid off Esquimalt BC. Last Canadian Pacific Fleet submarine until 2003 |
