Nummer: 21308
| Area : | Arctic Ocean |
| Sea area : | North Norway |
| Date of attack : | 22.04.1945 |
| Time of attack : | 08:50 |
| Nationality of U-boat : | German |
| U-boat : | U 997 |
| Commander : | Lehmann |
| Grid : | AC 8852 |
| presumed target type : | Steam Freighter |
| presumed tonnage : | 4000 BRT |
| presumed result : | sunk |
| Used weapon(s) : | Torpedo(es) |
| Convoy : | PK.9 |
| Date of observation : | 22.04.1945 |
| Time of observation : | 08:50 |
| Nationality of target : | Soviet |
| Actual type of target : | Steam Freighter |
| Name of target : | Onega |
| Year of launch : | 1924 |
| Actual tonnage : | 1603 BRT |
| Actual result : | sunk |
| Position of target : | 69.41n 33.17e |
| Footnote : | U-997 reported one big steamer damaged and a small one sunk, both in the same convoy. |
| Convoy : | PK.9 |
| Route of convoy : | Petsamo / Kirkenes - Kola Fjord (soviet) |
| Remark to convoy : | Since Nov 1944, annual new numbering (counter traffic = KP) |