Belfast Coastguard received a call at 4:45pm from a ferry passing the area reporting they had seen a RIB with no one on board between Ballycastle and Rathlin Island.
Coastguard Rescue Officers from Ballycastle and Portrush have been sent to the area. Belfast Coastguard have requested the launch of the Portrush RNLI all weather and Redbay RNLI inshore lifeboats and scrambled Rescue Helicopter 177 from RAF Prestwick to the scene.
Rob Steventon, Watch Manager, Belfast Coastguard, said:
"A major search is currently underway, with many other vessels in the area assisting. We believe the occupant of the boat may well have fallen overboard as there is rope caught around the propeller."