Nummer: 26022
| Area : | Indic Ocean |
| Date of attack : | 03.03.1942 |
| Nationality of U-boat : | Japanese |
| U-boat : | I-1 |
| Commander : | Ankyu |
| Grid : | W Australia |
| presumed target type : | Steam Freighter |
| presumed result : | sunk |
| Used weapon(s) : | Torpedo(es) + Gunfire |
| Date of observation : | 03.03.1942 |
| Nationality of target : | Dutch |
| Actual type of target : | Motor Freighter |
| Name of target : | Siantar |
| Year of launch : | 1921 |
| Actual tonnage : | 8667 BRT |
| Actual result : | sunk |
| Position of target : | 21.20s 108.45e |