Jose Salvador Alvarenga, 37, who says he spent more than a year lost at sea, certainly looked the part of castaway when he arrived in Majuro, the capitol city of the Marshall Islands, today.

The long-haired fisherman, who had a scruffy beard, smiled and waved to a crowd of onlookers as he clutched what would have been one of his first cans of Coca-Cola since he washed up on the remote Marshall Islands, some 5,500 miles away from Mexico. Despite the ordeal, Alvarenga was still chubby faced.

If it's true, his story is a real life version of the movie Castaway - minus a lovable volleyball named Wilson. Officials expressed cautious skepticism at the man's story as they worked to verify details.

Alvarenga, who said he got lost after a shark fishing trip off the coast of Mexico in December 2012, said he survived 13 months drifting in the Pacific Ocean by eating fish, birds and turtles, a representative at the Washington D.C. Embassy of the Republic of the Marshall Islands told ABCNews.com.

The man also scooped up little fish that swam alongside his drifting boat and ate them raw, while also drinking bird blood to quench his thirst, Thomas Armbruster, U.S. Ambassador to the Marshall Islands, told the Associated Press.

Alvarenga told officials he is from El Salvador but had been living and working in Mexico as a fisherman for 15 years before his ordeal.

In December 2012, Alvarenga said he left Mexico in a 23-foot fiber glass boat with a teenage companion named Ezekiel for what was supposed to be a day trip of fishing, the ambassador said.

(AFP/Getty Images)

A storm blew their boat off course, Armbruster said, and caused them to become disoriented and adrift. He said the castaway told him Ezekiel died a month later.

More than a year after Alvarenga said he left Mexico, he said he swam ashore on Ebon, a tiny atoll in the Marshall Islands, where news of his remarkable tale of survival quickly spread.

After a medical check is complete, Armbruster said the castaway hopes to go home.

"He's very anxious to get back in touch with his employer, and also with the family of Ezekiel," he said. "That's his driving motivation at the moment."

The Associated Press contributed to this report.

(Image Credit: AFP/Getty Images)