Compatibility summary
You will need a travel adapter in U.S. Virgin Islands; plug types used there differ from Germany. Voltage differs by more than 20% — a voltage converter may be needed for some appliances.
Plug comparison
Germany plug types: C F
U.S. Virgin Islands plug types: A B
There is no common plug type between Germany (C F) and U.S. Virgin Islands (A B). You need a travel adapter.
Voltage comparison
Germany: 230V, 50Hz
U.S. Virgin Islands: 110V, 60Hz
Voltage converter recommended (Germany 230V vs U.S. Virgin Islands 110V).