Mare Harbour is a small settlement on East Falkland, on Choiseul Sound. It is mostly used as a port facility and depot for RAF Mount Pleasant, as well as a deepwater port used by the Royal Navy ships patrolling the South Atlantic and Antarctica, which means that the main harbour of the islands, Stanley Harbour tends to deal with commercial transport. Mare Harbour berths will be improved with a £22 million investment. A daily bus service runs between Mare Harbour and Mount Pleasant.