This you have to see...
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Tom Keels
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This you have to see...
Tom Keels
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Wil
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<gross oversimplification follows>Sea Fox wrote:425 ft. deep seems awful deep. Can you really dive to that depth?
With the proper training you can, on trimix or heliox. The two main limiting factors on depth are narcosis (caused by inert gasses such as nitrogen), and oxygen toxicity.
Trimix is a blend of helium (a light weight inert gas that causes little narcosis), nitrogen (a heavier one, causes more narcosis), and oxygen. Heliox is straight helium and oxygen, no nitrogen.
You can tune your mix for the planned dive, for deeper depths using more helium, and less nitrogen. For anything much past 200 ft, you'll also have to lean out the oxygen to prevent toxicity, although you'll generally use a hypoxic (<21% O2) mix for depths a bit shallower than that even.
In cases where a hypoxic mix is used, you'll have to bring along a "travel gas", which is something that you can breath at the surface and during your descent. Once at a safe depth, you can then switch to your "back gas", which would be your trimix or heliox. You can see in one of the pictures he has a tank clipped off to his side. I would assume that is his travel gas. Generally a nitrox mix (air enriched with extra oxygen.)
Again, this is a gross oversimplification, there are many other factors that weigh in. Also, I'm not trimix certified, but I'm working on it. There's some deep cave stuff I'm hoping to do in the future, in the 300' range.
What really gets me is the fact that these guys are spearfishing at these depths. You really don't want to exert yourself at extreme depth. Bad things happen. I personally know a guy that got bent (decompression sickness) just from pumping his arm too much while doing a body recovery down at Eagles Nest (a cave near Tampa). The dive was only to 300', and the body he was lugging out weighed less than the fish this guy shot. While I wholeheartedly admire him, there's no way you'd catch me spearing past 200'. (Bigger balls, bigger fish I guess
)Wil
