Normally when a ship leaves the port the port's pilot is on board to make sure it gets out safely. Then the pilot is usually picked up by the Pilot boat and returned to port. Conversely, the pilot is dropped by the Pilot boat when a ship enters port.
In the case of the Port of Durban the pilot is dropped and picked up by helicopter. Durban is an extremely busy port on the South African coast and much time is saved by doing this because of the high number ships coming and going.
Credit: My own blog and video.
