Nummer: 22405
| Area : | Mediterranean |
| Date of attack : | 19.09.1940 |
| Time of attack : | 20:34 |
| Nationality of U-boat : | Italian |
| U-boat : | SERPENTE |
| Commander : | Tognelli |
| Grid : | 59sm St Maria di Leuca |
| presumed target type : | Submarine |
| presumed tonnage : | ts |
| presumed result : | damaged |
| Number of torpedoes/mines : | 1 |
| Used weapon(s) : | Torpedo(es) |
| Nationality of target : | Italian |
| Actual type of target : | Submarine |
| Name of target : | Colonna |
| Year of launch : | 1928 |
| Actual tonnage : | 791 ts |
| Actual result : | target visibly missed |
| Footnote : | "Serpente" erroneously fired against the Italian U-boat "Colonna", but luckily the torpedo didn't hit the target. |