Jose Salvador Alvarenga, 37, spent 13 months adrift at sea before washing ashore on the Marshall Islands. Alvarenga is currently undergoing medical treatment and officials on the island are working to piece together his story and if it proves true it would be one of the “greatest tales ever of survival at sea.”

The Telegraph reports Alvarenga, a fisherman, and another fisherman named Ezekiel went out to catch sharks off the coast of Mexico on Dec. 21, 2012. The boat’s motor broke down and the two fishermen were soon adrift in the Pacific Ocean following a storm blew them away from the coast of Mexico.

According to Alvarenga, Ezekiel stopped eating and died four months after being set adrift. Reports from the Telegraph and the Associated Press contradict the timeframe of Ezekiel’s death, with the latter stating the teen, between the age of 15 and 18, died a month after getting lost at sea.

Alvarenga washed ashore on the Ebon Atoll and a rescue boat transported him to Majuro, the capital of the Marshall Islands. The fisherman survived by catching birds, turtles and fish while drinking rain water when available, reports the Telegraph. Alvarenga did not keep track of the time and did not know how long he spent at sea but did say he wanted to commit suicide following the death of his boat mate, Ezekiel. “For four days I wanted to kill myself. But I couldn’t feel the desire – I didn’t want to feel the pain. I couldn’t do it,” said Alvarenga.

Originally from El Salvador, Alvarenga has three brothers who live in the United States as well as a 10-year-old daughter who lives in El Salvador.

Marshall Islands immigration chief Damien Jacklick said officials, including the U.S. Ambassador, are working to contact Alvarenga’s family and get the full account on his time at sea.

While the tale sounds extraordinary, some are question Alvarenga’s account of his time lost at sea. The Telegraph mentions Alvarenga had contradicting his story and he appeared to be in relatively good health despite being adrift for more than a year.

Speaking to AP, Gee Bing, acting secretary of foreign affairs for the Marshall Islands said he was unsure if he believed Alvarenga’s story. “When we saw him, he was not really thin compared to other survivors in the past. I may have some doubts. Once we start communicating with where he's from, we'll be able to find out more information,” said Bing.

The timing is pretty plausible, with strong currents bringing Alvarenga from Mexico to the Marshall Islands, notes AP citing Erik van Sebille, an oceanographer form the University of New South Wales. He said the trip would usually take between 18 months to two years but did not rule out 13 months.

Following a medical evaluation and treatment, officials plan to send Alvarenga back to Mexico. Officials are currently working to get in contact with his family and learn more about his incredible tale of survival.

A video of Alvarenga detailing his survival, courtesy of the Telegraph, can be viewed below.