Breathtaking undersea world of a 'Moscow Merman'

"One minute can pass by like a second. You close your eyes, and open them, and you're at the bottom and two minutes has passed already."

Molchanov can hold his breath underwater for 8.33 minutes.

But one of the few people in the world to hold their breath for longer was his mother -- Natalia Molchanova -- at 9.02 minutes.

Within the tight-knit freediving community, Natalia was known as the "Queen." The 41-time world record holder and her son Alexey were virtually inseparable on the circuit, spending up to nine months of the year traveling together to competitions across the world.

Sadly their journey was cut short in August last year when Natalia disappeared during a training dive off the coast of Spain.

Search efforts failed to find her body and the 53-year-old mother-of-two was presumed dead.

An influential figure in the sport, Natalia continued to break records, both in the pool and ocean, right up until her death. At the age of 47 she became the first woman to pass the 100 meter mark, diving with fins.

"She was a huge inspiration to me in the way that she lived her life," said Alexey, who was first taught to freedive as a teenager by his mother on summer holidays at the Black Sea.

Has his mother's death changed his relationship with the sea?

"I still love the ocean," says the sportsman who continues to both compete and train other freedivers.

"But it is a dangerous environment. And there can be some extreme conditions where not everything that happens is dependent on you."

Molchanov says he still feels safe in the water, secure in the knowledge there is always a team on hand should anything go awry.

"We do not dive to these depths without any preparation or accidentally," he says. "You cannot accidentally add 10 or 20 meters to the dive.

"If I dive 100 meters then it means I've already done tens of dives to 100 meters and below. So for me, it doesn't feel like something out of my control."

He believes that with the right training, almost anyone is capable of holding their breath for four minutes.

It's a skill with benefits above water too.

Suddenly a stressful day at work doesn't seem so bad, when you know the art of taking a deep breath -- "It's like a reload for your brain," he says.

Gaze at images of Molchanov gracefully floating underwater, his sleek frame free from bulky scuba gear, and it almost appears as though he's flying through space.

Indeed the sea's other-worldly beauty seduced both Molchanov and his mother -- and is perhaps the reason why even after her death, he keeps coming back.

"It's like visiting another planet," he says.

"There is this feeling of peace, of calmness, of weightlessness."

An emotional high, deep below the surface.