Events
On This Day - October 30
| 1905 | B2 | Launched |
| 1906 | C1 | Completed |
| 1913 | E8 | Launched |
| 1939 | Unique (N95) | Laid Down |
| 1939 | Upholder (N99) | Laid Down |
| 1939 | Urge (N17) | Laid Down |
| 1939 | Seahorse (S98) | HMS Seahorse sighted a submarine. An attack was started but before torpedoes could be fired the submarine dived. This was most likely U-21 which was patrolling in the same area but the U-boat did not observe the British submarine. |
| 1940 | Urchin (N97) | Launched |
| 1941 | Tireless (P327) | Laid Down |
| 1943 | Thorough (P324) | Launched |
| 1944 | Terrapin (P323) | HMS Terrapin sinks three Japanese sailing vessels with gunfire in the Malacca Strait. |
| 1944 | Tradewind (P329) | HMS Tradewind lays mines of the Mergui Archipelago, Burma. |
