An American man emerged after 66 days lost at sea, able to stand and walk without assistance after a "pretty remarkable" ordeal that experts say could be a textbook case for survival in the "Graveyard of the Atlantic".

Louis Jordan, 37, emerged from the more than two-month ordeal able to stand and walk without assistance after being airlifted to a hospital by the coast guard. He said he survived by eating rations, catching fish and drinking rainwater until a German tanker discovered him sitting on the hull of his overturned boat and waving his arms.

Jon Ehm, business development manager at survival education company Survival Systems USA, said that Jordan's claims are realistic.

"It proves that given a strong will to live and a little bit of ingenuity, a person can do quite well, with very little in the way of resource," Ehm said. "Well – surviving 66 days with no food or water and making do – he wasn't thriving, but definitely surviving."