A solo sailor was rescued from a heavy swell off the south coast on Tuesday night after his yacht capsized.
The man, believed to be French, managed to activate a personal location beacon (PLB) which alerted UK satellite monitors, who in turn contacted the Irish Coast Guard.
He was later found in the water clinging to the side of his 20ft yacht.
The UK's MCC (Mission Control Centre), formerly run by the RAF and now by the UK Coastguard, received his distress alert and satellite position about 32km (20 miles) south-southwest of Carnsore Point off the southeast tip of Ireland.
The Irish Coast Guard helicopter was launched from Waterford and located the sailor, who was described as shaken but unhurt. There were high swells but the cause of his capsize was not known.
He arrived back on shore at 9.19pm and was taken by ambulance to Waterford General Hospital as a standard precaution following exposure.
PLBs, which are also used by mountaineers and in other isolation sports, are increasingly common and often crucial in locating people in distress.
While the sailor would have activated the beacon, he would not have been aware of any response until he saw the helicopter’s approach.