Russian swimmer Yekaterina Nekrasova has set what is believed to be a new world record for the longest under-ice swim on Lake Baikal, traveling 85 meters (279ft) under 25cm of ice without a diving suit.
The 40-year-old needed nearly 1.5 minutes to swim the distance with a single breath, beating the previous achievement of 70 meters recorded by South African Amber Fillary in Norway last year.
Nekrasova bravely defied the freezing cold of -22C (7.6F), immersing herself in the icy water wearing neither a protective suit nor flippers.
In a video shared on social media, she can be seen quickly swimming beneath the thick ice of the world's deepest lake before a voice announced that she had set a new world record.
The achievement was recorded during annual 'Christmas on Lake Baikal' event, which is organized by local authorities.
It hasn't been announced whether the Guinness World Records has officially documented Nekrasova's breathtaking feat, which smashed the previous world record by 15 meters.