What it's like to free-dive 124 m below the ocean

William Trubridge barely moves as his body drops into the ocean. 

In front of him, a weighted rope extends down into the darkness of a large marine cavern called a blue hole. It's one of the deepest, bottoming out at 202 metres below sea level. 

Trubridge has no propulsion equipment, no fins, no oxygen and when he surfaces into the Bahamian sunshine 4 minutes and 24 seconds later, to wild applause, he flashes a tag showing he descended 122 metres into the watery crater, a world record until he beat it himself by diving to 124 metres just a few days later.   

Free-diving is diving on a single breath of air and it tests the body and mind like few other sports. 

Trubridge tells host Brent Bambury, it's the most euphoric and serene way to experience the ocean. 

"You're suspended down there in darkness. It's completely quiet," he says.

"It's very different than anything you could experience on the surface. The depth attracts all the stimuli that we're used to receiving; light, sound, the sensations of your body via points of contact and gravity. You tend to go inside yourself and experience your own consciousness more acutely," Trubridge says. 

Trubridge has been free diving for 13 years and setting world records since 2007.

When he was a young child his parents sold their home, bought a yacht and sailed around the world. But it wasn't the surface of the ocean he was drawn to. He had an affinity for the depths. 

Free-diving has become a popular sport. Since 1990 it has had its own organizing body with international competitors from around the world including Canada. 

Trubridge tells Bambury that much of the training has to do with the mind. 

"You have to be relaxed, focused," he says. Your brain wave frequencies are very low and minimal rational thought processes are occurring."

Trubridge says his training includes techniques such as meditation and visualization.

"Anything that allows you to program the subconscious mind so you don't have to think during the dive. If your body knows what to do, if your intuition and your muscle memory can operate on auto-pilot, then you can essentially turn off the rational mind that subconscious mind is actually a lot more accurate in those kinds of situations."

Dangerous sport 

Several high profile deep divers have lost their lives in training. That wasn't the case for Nicholas Mevoli. The 32 year old American died in 2013 soon after surfacing from a 72 metre free-dive. It was during a competition in  the same location where William Trubridge set his records last week. Trubridge witnessed the death.

"It was probably one of the saddest days for free-diving, but since then we have completely changed a lot of the protocols for deep free-diving. Definitely we haven't had another fatality since then."

He says he doesn't see his dives as being dangerous. 

"I'm comfortable with the risks I take," he tells Bambury. "The worst incidents that have happened to me involved blackout, a hypoxic blackout from low oxygen on the surface at the end of the dive. Coming to the surface you're going to blackout in the final phase of the dive when your oxygen level is at the lowest."

Trubridge will make another attempt to break his world record later in July. But that's not what drives him in free-diving. 

"I'm not setting targets or specific numbers. I'm just always trying to dive over my limits as deep as possible."

So is it the euphoria that motivates him? 

"Yes it can be. It's a beautiful place to be, under the water, and you learn so much about yourself through a dive like this."