One hectometer on one breath of air, unassisted.

This is old news, almost a year old, and he's actually broken this record since then. I think his record is now 105 meters. But I ran across this video and thought I'd post it.

William Trubridge was my instructor for my first beginning freediving class (when I dove to 42 feet). (Later, I took the intermediate and advanced classes from a different school, and dove to 90 feet. I'd like to make it to 100 feet.)

No-Limits freediving uses a weight to go down, and a float to come up.

Variable weight freedivers swim freely but drop weights at the bottom, making it easier to go both down and up.

Free-Immersion you pull yourself down and then back up on a rope.

Constant weight (which is what I do) you swim freely, and you keep all your weight on you, so you have the same weight coming up as you had going down. In competition you follow a line, and you are tethered to the line for safety, but you cannot use the line to assist you except for one pull at the bottom to reach the plate and start your upward swim. In competition you have 15 seconds from the time you break the surface to remove all your face gear (mask or goggles and nose clip) give an OK sign and say "I'm okay." (In the video you'll hear someone prompting him to remove his nose clip and to "say it.") You also must keep your airway above water (and not pass out) for 30 seconds.

Constant weight no fins is what William Trubridge does. Exactly the same as above, but without fins.

In this video he dove to 100 meters (330 feet) on one breath of air, unassisted. I presume the deep footage was taken by scuba divers using rebreathers, but they might have had automated cameras.

Assuming the same safety protocols as are used as where I took my other classes, the safety freedivers you see in the video will dive down and meet him at about 100 feet (1/3 his depth) though I don't know for sure if he uses the same numbers. The greatest risk of blackout is near the surface on the way back up, so the safety freedivers are there to bring him up if he blacks out.

At 100 meters the pressure is eleven atmospheres, and the volume of air in his lungs is compressed to 1/11 of its surface volume. With such a small volume of air it is extremely difficult to equalize the pressure in the middle ears to prevent damage to the eardrum. As a beginner, I was starting to have difficulty at 90 feet.

You will notice that at one point on the way down he stops swimming. This is the sink phase: The air in the lungs has compressed enough that he is negatively buoyant and does not need to do anything in order to continue downward.

Okay. Enough babbling. Here is the video:

[ame="http://vimeo.com/18213129"]William Trubridge 100 meter dive.[/ame]

 

He holds the world's record for CNF (constant-weight no-fins). I think the no-limits record is 706 feet.

You may have noticed him "packing" before he starts his dive. In order to increase the volume of air in the lungs, so as to have more air for equalizing the ears, freedivers first take the biggest breath they can, and then they use their mouth to force more air into the lungs. In training they do exercises to stretch the lungs so they'll hold more air, and exercises to allow more of an exhale. Either extreme can lead to lung damage if taken too far, so don't try it without proper training. It's impressive to see him on a full inhale, and on a complete exhale.

Also, for extreme freediving, in order to not have to expend air equalizing the mask, they wear water-filled goggles. (At my level, and even considerably beyond my level, a low-volume mask is adequate. But I've watched some world-class freediving where water-filled goggles were used.)