Quote:
Originally Posted by Oberon
Wow...100 meters...and what's more, done without a weight or float bag. Normally they are carried down by a weight and then brought slowly back up by a float bag to prevent the bends but not this guy.
Kudos to him to pulling it off, could have quite easily not been so lucky.
Done for a good cause too.  |
You can't get decompression sickness (the bends) doing a surface dive. At that level you're almost at 7 atmosphere's in pressure, without scuba gear am amazed that the body is able to take that much pressure without imploding from the intense pressure of the water.
Reason people get the bends is that when you are deep underwater (at least 45m/100 feet and of course anything deeper) you take in more O2 to compensate for the pressure that the water is exerting on your body. If the same diver has scuba gear on, he'd be taking rougly 7x the amount of O2 per breath than on the surface. The internal pressure of the lungs must match that of the outside so you start using more O2 the deeper you go.
Problem is the ascent, to properly ascend from any depth below ~25m/50 feet you are supposed to exhale the entire time you are ascending so that all that extra O2 gets out of your body. If you don't exhale all that air in the lungs has to go somewhere, and the nitrogen portion that is naturally in the air enters into your body and is was makes you sick. Thus the need for decompression chambers to slowly reduce the pressure against the body that happens while in the water. Pressure is then reduced slow enough that the nitrogen passes out of your body naturally (through exhaling) and can be the difference between life or death.
Had the skin diver had a scuba diver there at 100m and he taken some air from his tank, then he would be potentially subject to decompression sickness - if he didn't exhale the entire time he was ascending to the surface. Since he didn't, there wasn't an excess of O2 in the lungs that would happen using scuba gear, so the body is in no danger of having nitrogen getting pushed into the body. His biggest worry is drowning!