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