Andrew Nurse and Robert Beggs spent more than eight hours clinging to their upturned life-raft after abandoning the craft late on Wednesday night. They were finally picked up by a coastguard helicopter at first light.
Their shipmate - a 33-year-old so far been identified only as Ray - was washed away from the yacht in the Bay of Biscay, about 150 miles off the French coast.
Mr Nurse, 33, of Kilburn, north-west London, said the three men were taking the yacht Ocean Madam from Malta to Plymouth. After they reached the northern Spanish port of La Coruna, they ran into seriously bad weather, he said.
Speaking from Brest Military Hospital in Brittany, where he and 37-year- old professional yachtsman Mr Beggs, from Plymouth, are recovering, he said: "It was blowing a force seven or eight gale and then it went up to nine, and the waves were massive.
"The yacht just flipped right over onto its roof. I was panicking because the cabin was filling up with water and I didn't know how to get out. Everything was flying about the cabin. It was chaos.
Mr Nurse and Mr Beggs - both members of the Territorial Army, like the missing man - managed to set off an emergency beacon to alert coastguards, and got into the boat's liferaft. "Ray" was believed to have gone missing when the craft turned over.
"The worst thing was listening to Ray blowing his whistle, and not being able to see where he was or work out what direction the sound was coming from."
Later the men had to cling to the raft when it too was upturned. "It was bitterly cold, and we were trying to keep warm, but the adrenalin was pumping so hard I barely noticed how cold I was. I just wanted to live." A helicopter was called out, but was unable to reach them until it was light enough to locate them.Reuse content