Nummer: 11903b
| Area : | Western Area |
| Sea area : | Carribean Sea |
| Date of attack : | 27.08.1942 |
| Time of attack : | 06:23 |
| Nationality of U-boat : | German |
| U-boat : | U 511 |
| Commander : | Steinhoff |
| Grid : | EC 1299 |
| presumed target type : | Tanker |
| presumed tonnage : | 9000 BRT |
| presumed result : | sunk |
| Used weapon(s) : | Torpedo(es) |
| Convoy : | TAW.15 |
| Date of observation : | 27.08.1942 |
| Time of observation : | 05:35 |
| Nationality of target : | Dutch |
| Actual type of target : | Motor Tanker |
| Name of target : | Rotterdam |
| Year of launch : | 1925 |
| Actual tonnage : | 8968 BRT |
| Actual result : | sunk |
| Position of target : | 18.09n 74.38w |
| related attacks : | Angriff 1 Angriff 2 |
| Convoy : | TAW.15 |
| Route of convoy : | Trinidad - Aruba - Key West |
| Remark to convoy : | Jul to Aug 1942, then TAG. Counter traffic = WAT |