Nummer: 17803b
| Area : | Western Area |
| Sea area : | North Atlantic |
| Date of attack : | 11.02.1944 |
| Time of attack : | 00:12 |
| Nationality of U-boat : | German |
| U-boat : | U 731 |
| Commander : | Keller |
| Grid : | BE 2996 |
| presumed target type : | Destroyer |
| presumed result : | sunk |
| Used weapon(s) : | Acoustic homing torpedo (gnat) |
| Convoy : | KMS.41 |
| Footnote : | U-731 fired a spread and assumed two hits on a steamer, and heard a gnat detonation after 2:30 min. |
| related attacks : | Angriff 1 |
| Convoy : | KMS.41 |
| Route of convoy : | United Kingdom - Gibraltar - Port Said (slow) |
| Remark to convoy : | Since Oct 1942; since May 1943 combined mit OS in Atlantic (counter traffic = MKS) |