A family of four are "incredibly lucky to be alive" after spending two hours in the sea desperately clinging to a sinking vessel in Carmarthen Bay.

A 15-year-old boy, his grandfather, uncle and great uncle got into difficulties while fishing halfway between Amroth and Pendine last Thursday evening.

John, Andrew, Meurig and David Matthews, who are all from Ammanford, had set out earlier in the afternoon aboard their vessel 'Nonina III', but were hit by a wave throwing them all to one side of the boat at around 6.30 pm.

The 15-foot vessel quickly filled with water and began to sink, but stayed afloat by the bow.

The teenager and the men, aged 65, 59 and 43, had no lifejackets on and did not have any flares on them, so spent some time attempting to get their equipment out of the bow.

Eventually, the youngest member of the party, David, managed to reach two hand-held red flares. One of the flares was fired, but was upside down and went into the water. The second flare was fired and was successful.

The flare was spotted by three separate people who called 999 and reported the sighting to Milford Haven Coastguard.

The first was received from a police officer and his partner on holiday in the area from Hertfordshire who saw the flare off Amroth through a pair of binoculars they had bought earlier in the day, while the second report came from Marros and the third from Saundersfoot.

Milford Haven Coastguard took a cross bearing of all the three sightings and requested Tenby inshore lifeboat and the all-weather, RFA Sir Galahad lifeboat to launch shortly before 8 pm. Tenby Coastguard were also requested to assist and went to Ragwen Point, which was the cross point which had been gained from the three sightings.

When the ILB was a mile off Ragwen Point, Milford Haven Coastguard requested it to fire a white flare in the hope that it would invoke a response from those in difficulty.

A few moments later, the inshore crew picked up 59-year-old Andrew Matthews who had been attempting to swim ashore.

He reported that three others were in the water, so a rescue helicopter from RAF Chivenor was scrambled to join in the search.

The three others were soon recovered from the water by the inshore lifeboat and all four were transferred on to the RFA Sir Galahad and taken to Saundersfoot Harbour where they were met by two awaiting ambulances and the helicopter which had landed on the beach.

After being treated by paramedics, they were flown to Withybush Hospital, Haverfordwest, suffering from hypothermia. One of the men, who had a previously broken arm, which was in a sling, had also ingested some motor fuel.

Nigel Porter, Milford Haven Coastguard watch manager: "These men are incredibly lucky to have survived this ordeal. Their story could so easily have been far more tragic.

"The fact that three separate people saw their red flare and knew to report it to the Coastguard is very fortunate. They all spent two hours in the water clinging to the wreckage of their boat, which in itself is no mean feat.

"One of them had attempted to swim to shore in a desperate effort to raise the alarm. He was the first one to be picked up and it would have been highly unlikely that he would have reached the shore.

"The weather was reasonable, although as it was approaching dusk and with only moderate visibility, searching could have been difficult if it had not been for the three independent sightings.

"This incident highlights the importance of red flares and the fact people should not fire them unless assistance is urgently needed. In this particular case, carrying the red flares certainly made a huge contribution to saving these men's lives."

A spokesman for the RNLI said: "The men were extremely lucky that the ILB picked them up in time."

After treatment, all four casualties were released from hospital during the early hours of Friday morning.