A teenage boy has been rescued off the coast of Alaska after being stuck adrift on an upturned boat for days.

Derek Parker Aghnaanga was aboard a fishing vessel when it capsized on the Bering Sea, killing two of his family members.

The 15-year-old’s boat was expected to return to Savoonga, a small village on the northern tip of St Lawrence Island, on Sunday, September 6.

Two days prior, Parker had set sail with his 35-year-old brother, Sidney Kulowiyi, and their cousin, whose name and age have not been disclosed.

It is understood that the family worked in fishing and at one point over the two days, a fishing line got caught in the boat’s motor.

Another family member, Darren Toolie-Noongwook, told NBC News that Sidney had gotten tangled in the lines after attempting to pass a life jacket to his brother, causing the boat to capsize.

Darren told the network that Sidney was ‘the first to go’, while Parker and his cousin were able to climb on top of the overturned boat.

He explained that after surviving the night, the cousin started to panic about being stranded at sea and ‘jumped ship’.

Darren said that the cousin swam around five to six feet before drowning in the icy waters.

Meanwhile, Parker remained kneeling on the hull of the boat and praying to be rescued until US Coast Guard members spotted him on Monday, September 7.

While the Coast Guard received a report about the missing boat on Sunday night, rescue efforts had to be halted until the following day because of poor visibility.

The agency stated that a Hercules aircrew identified the boat just under 13km from its last known position at around 3pm local time on Monday.

The Coast Guard deployed a rescue craft and alerted nearby vessels to join the recovery mission.

The captain of the vessel that rescued Parker, Adam White, told NBC News that he blasted his boat’s horn several times ‘to give him some hope’ that help was on the way.

His team was returning from conducting an official ocean survey when they received the message from the Coast Guard.

Parker was filmed in a black hoodie kneeling on the overturned boat when the crew found him, before he climbed aboard their vessel.

The captain told the network: ‘When he finally came into view, it was elation from everybody. Everybody cheered.’

The Coast Guard stated that Parker was showing symptoms of mild hypothermia, but has since received medical attention.

The agency added that the bodies of the two others from the fishing vessel were later recovered from the water and transported back to land.