A world record freedive 70m beneath the ice | 7.30

As if diving a hundred metres down towards the ocean floor on just one breath of air isn't difficult enough, a freediver from Victoria decided to set himself the challenge of breaking the record for the deepest dive under ice.

"What if I go to the edge of my sport, the outer edge of an already quite extreme sport, what would happen if I started playing around that edge?" he asked himself.

Today that risk turned to reward as he broke the record for the deepest dive under ice, reaching a depth of 70 metres.

"The record dropped today!" he confirmed.

Speaking to 7.30 from a remote location in northern Norway, Williams said the dive, which was overseen by Guinness World Records, was tough.

"I got a successful dive to 70 metres under the ice.

"The dive took much longer than I was expecting and it was vastly harder than I thought it would be."

The risks of freediving are well documented.

To freedive under the ice is even more dangerous.

Freedivers have reached depths of more than 200 metres below the surface, but under the ice, it's less than half that depth.

"When I first looked at what the world record was under the ice, I found it was 65 metres and I thought to myself, why is it so much shallower than the world record away from ice?"