Sixteen of the crew scrambled onto the upturned hull of Rambler 100 but five others, including a woman with hypothermia, ended up in waters about eight nautical miles off the Fastnet Rock.
The rapidity of the yacht’s total inversion took all of the 21 crew by surprise, an investigation shows.
Baltimore RNLI lifeboat rescued most of the crew, but the five in the water were saved by a diving boat taking photographs of yachts participating in the Rolex Fastnet Race in Aug 2011.
However, due to confusion over registration of personal location beacons, the emergency services were searching for two PLBs whose registration did not identify their boat.
Keel failure, it emerged, led to the dramatic capsize.
A report by the Marine Casualty Investigation Board, published yesterday, did not reveal the reason for the fracture and detachment of a major portion of the keel on the super yacht.
The 72-page report said it did not investigate this as the damaged yacht had been towed to England, shortly afterwards, for repairs.
However, among the MCIB’s recommendations was top racing yachts should be required to carry their automatic identification system antenna at mast head to facilitate stronger automatic ID signals. A further recommendation was flag-state authorities should instigate an investigation as to why the keel failed and disseminate any recommendations/technical guidance following an investigation.
An emergency position-indicating radio beacon had worked, however, and as intended, had initiated the rescue process.
Last year, another review by US authorities found the total survival of the crew was due to “training, experience and calm manner of handling this horrific incident by a group of world-class professionals”.
Owned by US-based Speedboat Racing Ltd, the 33-tonne Rambler 100, with a mast height of 154ft, was registered in the Cayman Islands.
It had rounded the Fastnet Rock and was sailing in a south-south-west direction.
About 20 minutes into the beat and having covered approximately four nautical miles, a loud bang was heard by all on board and the boat heeled suddenly to starboard. She continued to heel over until the mast and sails hit the water. After momentarily slowing, the boat quickly “turned turtle”, coming to rest in an inverted position.
The report said 11 crew were on deck and 10 were below decks at the time.
The dive boat Wave Chieftain rescued the five people in the water, including Wendy Touton, suffering from hypothermia. She was airlifted by coastguard helicopter to Tralee General Hospital. All other crew were taken to Baltimore.