The Marine Accident Investigation Branch (MAIB) has launched an investigation after one man died and four others were rescued after their yacht reportedly lost its keel and overturned on Saturday morning. A major search and rescue operation was launched at 0400 after a merchant vessel reported seeing red flares, approx seven miles off Prawle Point, South Devon.

Attempts were still underway yesterday to salvage the 35ft Solent-registeredHooligan V, a Max Fun 35, which was drifting submerged off the south Devon coast. Peter Hodges, of Salcombe Lifeboat told BBC news: “The keel completely parted company with the boat. Either it must have struck an underwater obstruction or else there would have been a fault with the boat and the attachment of the keel to the boat. One of those two things must have happened.”

The four surviving crew were picked up by the merchant shipLaarand transfered by helicopter to hospital in Plymouth where they were treated for hypothermia. The MCA reported conditions of Force 5, with good visibility and 1m swell.

Chris Winzar, RNLI coxswain at Salcombe, told the Guardian newspaper: “It is a very sad outcome and our thoughts are with the yacht crew and their families at this terrible time.”