Deep blue

Posted on July 14th, 2008 by george.
Categories: animals, environment, fun, future, life, sports, travel, video, water, youtube.

In spite of childhood swim lessons in frigid water at the crack of dawn (or perhaps because of them), I have always been a waterbaby.  In the past six months I’ve made rapid progress in scuba diving, beyond PADI certified rescue diver into specialties like wreck penetration diving.  Lately I’ve become obsessed with the geology and location of blue holes, occuring in equatorial karst regions throughout the Caribbean and across the globe, ranging from the cenotes of Mexico to the springs of Florida to the blue holes of the Bahamas, Belize, and the Red Sea.  In exploring online what I hope to someday explore in person, I ran across this video and was entranced.  If you can’t see yourself doing this, then imagine you were along with Lorenia today, as she swam in the azure waters off the Yucatan with massive sea turtles and giant whale sharks, exploring undersea caves and catching rides from 12-foot wide manta rays.

7 comments.

atoosa

Comment on July 18th, 2008.

This is unbelievable. I too was entranced. This has to be at the limit of human capability with respect to breath control and athletic ability. While watching it, I felt this deep longing to be able to be one with the ocean like that (without my SCUBA equipment). I too am a child of the ocean, it’s where I feel most at home — I feel this deep bonding with the earth when submerged in the sea. I always thought it was because I grew up on the shores of the Caspian, but I’ve also wondered if it has to do with primordial memory – something in my genes that “remembers” when humans lived in the sea.

Andrew

Comment on July 18th, 2008.

YES.

nas

Comment on July 21st, 2008.

Sorry friends, but I don’t buy it. 58 meters deep without a scuba suit? Not only can humans not hold their breaths for the amount of time it takes to get that deep, but your eardrums could easily pop and you could get nitrogen narcosis — that even happens to people in scuba suits at 200 feet. Also, he ascended way too quickly to not get the bends (if he was indeed at 58 meters).

I could maybe believe 38 meters horizontally without a breath, if you’re one of those extraordinary and well-practiced humans who can hold your breath for 2 or 3 minutes. I agree that this all looks peaceful and inspiring and amazing, but, without some extrinsic corroboration of the facts, I just don’t think the depth supposedly portrayed here is really possible — which means I’m not quite wowed at the moment.

(Btw, sorry to ruin the party. I am only a week away from the bar exam, so that could definitely be accounting for some of the cynicism and and inability to share in the joy here).

nas

Comment on July 21st, 2008.

One last thing — how could there even be light at 58 meters? There was a lot of sunlight in this video… way too much, it seems, for him to be that deep.

george

Comment on July 21st, 2008.

Nas joon, a few things.

First, I am the resident debunker at my office and among my friends. I would not post anything here without vetting it first.

Second, it seems law school might be getting to you. Balanced skepticism is a useful tool, but too much cynicism is unhealthy. I do sympathize about the bar, however, and understand how it could color your take.

Third, a quick wiki of freediving will corroborate not only this independently verified video of William Trubridge (who incidentally holds the record for the freediving discipline of “static weight without fins” — 86 meters), but also reveal to you other seemingly impossible records. For instance, the men’s world record for static apnea (breath holding) is 10 minutes 12 seconds. This video was less than half that, muscle fatigue notwithstanding. The mammalian diving reflex is an amazing adaptation, and it’s built right into our genes. I’m don’t approach the same league (get it?) as these athletes, but I will tell you I can free dive with fins to a depth of 15 meters for two minutes, and that’s with no steady practice.

http://en.wikipedia.org/wiki/Free_diving

http://en.wikipedia.org/wiki/Mammalian_diving_reflex

Now to your specific points.

1) William is wearing a special mask here that clamps his nostrils shut, so that he can clear his ears without using his hands. You are correct to point out that the water pressure on the outside of the eardrum will increase (in fact, by one atmosphere, or double, every 32 feet). But this is easily balanced by forcing a small volume of air from your lungs into your inner ear. All divers must do this in order to descend, scuba or otherwise. On ascent, the greater pressure in your inner ear escapes through your eustachian tubes naturally, and does not require a Valsalva maneuver. As an aside, the volume of air in your lungs decreases with increasing depth, so there is a theoretical point at which you will run out of air in your lungs with which to equalize your inner ear.

http://en.wikipedia.org/wiki/Mammalian_diving_reflex

http://en.wikipedia.org/wiki/Valsalva_maneuver

2) Nitrogen narcosis can occur as early as 66 feet, or 20 meters depth. It’s not an instantaneous phenomenon; for those who are susceptible to it, it increases with depth, not unlike having another beer. Many people do not experience it until great depths (did you know that technical scuba divers have descended past 1000 feet?). You can build a tolerance to nitrogen narcosis, and you’ll notice that at every step of the way, trained rescue divers (acting as videographers) were stationed to assist Trubridge in the event of a blackout.

http://en.wikipedia.org/wiki/Deep_diving

3) Both nitrogen narcosis and the bends can be addressed by the simple fact that at no depth did he actually breathe. The bends occurs due to a buildup of pressurized nitrogen in your bloodstream. Any recreational diver can tell you that it’s not just depth that contributes to DCS (decompression sickness, as divers refer to the bends), but time. Recreational divers are strictly limited to a depth of 130 feet, and it’s recommended not to go past 100. This is in order to avoid decompression stops on ascent, where you would rest at an intermediate, shallower depth, at breathe slowly in order to release excess nitrogen in your bloodstream through your lungs. What’s happening at great depths when you’re on scuba is that you are introducing great gulps of pressurized nitrogen into your bloodstream with every breath you take, at a higher partial pressure than you would at sea level. This nitrogen builds up, and you are correct to point out that it must be released slowly as you ascend to lower pressures so that it doesn’t expand out of solution to form bubbles in your blood that collect where your vessels pass through your joints. The bends is not an issue in freediving because compared to scuba diving, you spend very little time at depth, and most importantly, you only have as much nitrogen in your bloodstream as you had when you took that single breath.

http://en.wikipedia.org/wiki/Nitrogen_narcosis

http://en.wikipedia.org/wiki/Decompression_sickness

4) As I mentioned above, the world record for breath holding is over ten minutes, so it’s entirely believable that Trubridge stayed down for under five.

5) The absolute limit for light penetration is 200 meters. You will notice in this video, however, that everything appears blue at 58 meters (except for when the videographer’s light illuminates Trubridge’s body). This is because the red wavelength of visible light is scattered easily by water (ever wonder why the oceans are blue?). Blue light travels furthest in water. 58 meters is around 180 feet, so about twenty feet further than this you’re right: everything would go to black.

All that said, who would go to the trouble of creating such a wildly realistic hoax? Perhaps you’ve been watching too many fake videos, or postmodern society has been grinding on you too long. Some things in this world are just plain jaw-dropping and awe-inspiring. Freediving is one of them.

Now watch it again and believe.

Eli

Comment on September 15th, 2008.

Hey Jorge, remember that day we went to Crystal River years ago and went to the bottom of the Three Sisters without tanks?

That was awesome!

I tried to train to do the mammillion diving reflex one summer when I was lifeguarding. Never tried it at depth, but I got it right one time. I did three lengths of a 50 yard pool in just under 3 minutes. It was pretty freaky, man…even horizontally.

george

Comment on September 15th, 2008.

Eli! So great to see a comment from you here. I must admit, I was skeptical when you first mentioned the reflex; I hadn’t heard of it before. I do remember Crystal River…how is it that memories in nature are so clear, so vivid, and always among the best? I believe you on the three minutes, and I have experienced the freakiness. Two minutes at the bottom of Wekiva Springs gave me enough time to explore two caves I’d never seen before, and never knew went so deep!

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