A British ship that was once a lifeline to the outside world for St. Helena has begun its last voyage to the remote South Atlantic island where Napoleon died in exile.

The RMS St. Helena on Wednesday left the South African city of Cape Town on a final round-trip journey of three weeks to St. Helena and Ascension, another British-ruled island. After that, another ship will transport cargo about once a month to St. Helena.

The only means of regular passenger travel will be by air, thanks to a South African airline that started a weekly commercial flight in October after the delayed opening of an airport.

Ship mechanic Lionel Peters says the "royal mail" vessel, which sailed to St. Helena for nearly three decades, will be missed.