A special alert is to be broadcast warning ships of a Vauxhall Corsa that is floating across the Bristol channel.
Swansea Coastguard say that the vehicle, believed to be a hire car, could be anywhere in the channel after it sank whilst parked a sideroad in Mumbles, Swansea.
The car has now disappeared, despite efforts to rescue the vehicle during low tide in the early hours of 29 November. It is reported to be a silver 61-plate car.