An Irish reality television show nearly sank without trace on Friday after the ship carrying contestants around the country's treacherous coastline hit the rocks and broke up.

Terrified contestants taking part in state broadcaster RTE's "Cabin Fever" programme were winched to safety by helicopter after the boat they were supposed to stay aboard for eight weeks ran aground near Tory Island, Donegal, in northwest Ireland.

A producer with the company making the programme -- flagged as the Irish television event of the summer -- said all precautions had been taken, the ship thoroughly checked before setting out and the crew trained in sea survival.

"I have no idea how it happened," he told RTE.

He said the incident had not been caught on film as the camera crew had not been on duty.

"(But) we would rather not have one hell of a programme -- we would rather have a safe ship," he said.

Lifeboats rushed to the ship's aid after crew members sent out a distress call on Friday afternoon.

RTE said the vessel, carrying 10 contestants competing for a cash prize, the camera team and ship's crew, had later "completely broken up" and was "unsalvageable".

However, it added the show would go on. A replacement ship was being found in England, and filming of the endurance test contest -- an Irish version of British reality TV hit "Big Brother" -- would continue on nearby Tory Island.