Events
On This Day - October 30
| 1905 | B 2 (I 22) | Launched |
| 1906 | C 1 (I 31) | Completed |
| 1913 | E 8 (I 88) | Launched |
| 1939 | Unique (N 95) | Laid Down |
| 1939 | Upholder (N 99) | Laid Down |
| 1939 | Urge (N 17) | Laid Down |
| 1939 | Seahorse (S 98) | 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 (N 97) / Sokół (Dutch) | Launched |
| 1941 | Tireless (P 327) | Laid Down |
| 1943 | Thorough (P 324) | Launched |
| 1944 | Terrapin (P 323) | HMS Terrapin sinks three Japanese sailing vessels with gunfire in the Malacca Strait. |
| 1944 | Tradewind (P 329) | HMS Tradewind lays mines of the Mergui Archipelago, Burma. |
