Nummer: 28012
| Area : | Pacific Ocean |
| Sea area : | South Pacific |
| Date of attack : | 06.08.1942 |
| Nationality of U-boat : | Japanese |
| U-boat : | Ro-33 |
| Commander : | Kuriyama |
| presumed target type : | Steam Freighter |
| presumed result : | sunk |
| Used weapon(s) : | Gunfire |
| Date of observation : | 06.08.1942 |
| Time of observation : | 10:34 |
| Nationality of target : | British |
| Actual type of target : | Motor Freighter |
| Name of target : | Mamutu |
| Year of launch : | 1938 |
| Actual tonnage : | 300 BRT |
| Actual result : | sunk |
| Position of target : | 09.11s 144.12e |
| updated on: | 00.00.0000 |
| Remark: | Mamutu- |