“Brains” Editorial Facts Challenged; Mixed Gas Safer?

Dale,
I read Ken Kurtis’ guest editorial last month, and while I share his view respecting a common sense approach to a dive, I must take issue with his facts. Sadly, the last 12 months have seen several fatalities, but none of these fatalities relate to divers diving on mixed gas as Ken suggests. While I appreciate your view respecting decompression diving, it still warrants consideration that divers routinely dive deeper than recommended depth limits, and to the extent a diver engages in this practice, isn’t it safer for them to do so on a hyperoxic or normoxic trimix? The chosen gas transcends the deco- vs. no-deco debate and speaks to a clearer head at depth and allows for greater cushion against the NDL limits.

Regards
Michael H. Kane
via e-mail

First to clarify the facts, a response from Ken Kurtis:
Tony Maffatone (he was the guy with a seven-tank, 600cf rig) died on August 2, 2000, on the wreck of the San Diego in New York. According to George Horn, who’s the owner of Scuba Divine in New York and was a good friend of Tony’s, confirmed that Tony was diving mixed gas.
Ken Kurtis

Response from Dale:
While Ken and I do not agree on everything, the point of the guest editorial, I think, was not that one kind of diving technique was safer than the other (tec, rec, rebreather, mixed-gas, etc.) but rather that in ANY diving situation, you have got to have ALL your ducks in a row for a truly safe dive, and that is best done by thinking through, carefully, each and every part and contingency of your dive plan. This goes for shallow, deep, decompression, nitrox, air, mixed-gas, even free-diving.
Dale Sheckler
Editor

Why Salt Crystals in Tank?

Hello,
Possibly you could provide me with the reasons why salt crystals form in the inside/bottom of air cylinders :aluminium? Is it the high pressure in the cylinder combined with salt vapor from surrounding air at the air refilling station? Or is it just salt water that has leaked into the tank?

Thanks
Dean
(currently in Malaysia, but from So. Africa)

Dean:
It is most likely salt air moisture from the compressor. Moisture will come out of the air when compressed just about anywhere it comes from, but it is usually in the form of fresh water. If it is salt water, the intake for the compressor is much too close to the surface of the ocean (it only needs to be a few feet up, free from saltwater splash). In addition, moisture should be filtered out of air before entering the cylinder. Any substantial moisture getting into the cylinder is a result of poor filtering. Moisture in the cylinder is not bad for the health of the diver, but the cylinder will suffer, especially from saltwater moisture. Saltwater will also damage a compressor.
One final point: Be sure what you are seeing is not just aluminum oxide (a common problem).
Dale Sheckler
Editor

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