Events
On This Day - November 20
| 1917 | H33 | Laid Down |
| 1917 | H34 | Laid Down |
| 1917 | H47 | Laid Down |
| 1937 | O22 (Dutch) | Laid Down |
| 1939 | Undine (N48) | HMS Undine departed Rosyth for Blyth where she arrived later the same day. |
| 1940 | Unbeaten (N93) | Completed |
| 1943 | Sibyl (P217) | HMS Sibyl sinks two Greek sailing vessels with gunfire in the Gulf of Saloniki, Greece. |
| 1944 | Spark (P236) | HMS Spark sinks a Japanese sailing vessel with gunfire of the Mergui Archipelago, Burma. |
| 1944 | Tally-Ho (P317) | HMS Tally-Ho sinks the Japanese auxiliary minelayer Ma 4 about 30 nautical miles east of the southern tip of Great Nicobar Island. |
| 1976 | Sceptre (S104) | Launched |
| 2009 | Astute (S119) | Arrived at Faslane for the first time. The submarine's arrival on the Clyde marks the beginning of a process that will see Faslane become the UK's sole operating submarine base over the next decade. |
