A Russian man rescued after 67 days adrift in a small inflatable boat in the Sea of Okhotsk described Wednesday how he survived by battling shivering cold and drinking rain water.

Mikhail Pichugin, 46, had set off to watch whales with his 49-year-old brother and 15-year-old nephew. But the boat's engine shut down on their way back on Aug. 9.

Initial efforts by emergency services to locate the trio failed. Pichugin's brother and nephew later died He tied their bodies to the boat to prevent them from being washed away.

A fishing vessel spotted the boat this week and rescued Pichugin about 11 nautical miles off Kamchatka, about 1,000 kilometres from its departure point.

Speaking to reporters Wednesday from his hospital bed, Pichugin described how the boat's engine broke down and then one of the oars broke, making the boat uncontrollable.

The phone on board was useless as there was no network coverage, but the trio used it for geolocation for a week until the phone battery and a power bank ran out. They tried unsuccessfully to attract rescuers' attention using the few flares they had.

"A helicopter flew past close, than another one after three days, but they were useless," Pichugin said in comments broadcast by Russian state television.

Struggled to stay warm

He said they collected rain water and struggled to get warm on the sea off eastern Russia.

"There was a sleeping bag with camel wool, it was wet and didn't dry," he said. "You crawl under it, wiggle a little and get warm."

They had a limited stockpile of noodles and peas and tried to catch some fish.

Russian media quoted Pichugin as saying his nephew died of hypothermia and hunger in September. His brother started behaving erratically and tried at one point to jump off the boat.

Pichugin said he survived "thanks to God's help."

"I simply had no choice. I had my mother and my daughter left at home," he added softly.

Doctors at the Magadan hospital said he was suffering from dehydration and hypothermia but in stable condition.