Nummer: 17609
| Area : | Western Area |
| Sea area : | North Atlantic |
| Date of attack : | 30.12.1943 |
| Time of attack : | 05:28 |
| Nationality of U-boat : | German |
| U-boat : | U 421 |
| Commander : | Kolbus |
| Grid : | BE 6592 |
| presumed target type : | Destroyer |
| presumed result : | sunk |
| Used weapon(s) : | Acoustic homing torpedo (gnat) |
| Convoy : | E.G. |
| Actual tonnage : | ---- -- |
| Actual result : | hit not ascertained |
| Footnote : | U-421 heard a gnat end-of-run detonation after 10 min. |
| Convoy : | E.G. |
| Route of convoy : | Escort Group |
| Remark to convoy : | British Task Group in Atlantic |