Nummer: 21511
| Area : | Baltic Sea |
| Sea area : | Gulf of Finland |
| Date of minelaying : | 26.06.1941 |
| Nationality of U-boat : | Finnish |
| U-boat : | IKU-TURSO |
| Commander : | Pekkanen |
| Grid : | F11 barrage |
| presumed target type : | --- |
| presumed tonnage : | ---- --- |
| presumed result : | hit not ascertained |
| Used weapon(s) : | Sea mine(s) |
| Date of sinking : | 29.08.1941 |
| Nationality of target : | Soviet |
| Actual type of target : | Fleet Tug |
| Name of target : | Balkhash (No.501) |
| Year of launch : | 1918 |
| Actual tonnage : | 2191 BRT |
| Actual result : | sunk |
| Position of target : | near Vaindlo |
| Footnote : | On mine barrage F.11 (laid on Jun.26th by "Iku-Turso") may have been sunk "Aksel' Karl" and possibly "Balkhash", if there was no further barrage near Vaindlo. |