An unmanned lifeboat 1 has a hull 2 with a transom opening 3, a fo'c'sle 4 closed by a rounded top deck 5, providing accommodation 6 for survivors. The aft deck as such is generally U-shaped with a cut-out 16 open at the transom17, which is vestigial with two small port and starboard parts. Within the cut-out is a boarding assistance ramp 18. This is level with the aft deck at its forward end and slopes down to the transom. It extends aft of this by a few of feet—say about 1 m—to enable survivors to swim and crawl onto it.
For guidance to reach the vicinity of the survivors, the lifeboat is equipped with a communication apparatus including a receiver 32 for receiving survivor location data. In addition, the navigation apparatus with which the lifeboat is equipped includes a GPS system 33 of its own, a compass 34.