American tourist dies while diving Cozumel caves.....

[tadawson]

No, the shop is responsible for the quality of the air they pump. If you don't want to trust them to meet their responsibility, and even despite that mistrust still choose to do business with them ... that's fine, you clearly should have your own analyzer.

And I choose the shop - so ultimately, *I* am still responsible.

- Tim

[Thalassamania]

It was the fills from the boat based compressor that caused the corrosion of that cylinder. I'm pretty certain oil was only one of the issues. "Most all" is not all. And how about all the near misses that didn't result in deaths?

I don't know how many compressor complexes you have been responsible for in your lifetime, but just in case it was zero, here are the facts:

• corrosion in a cylinder is caused by water, especially salt water,
• oil in a tank does not mean CO in a tank,
• oil in a tank will slow corrosion.

So please, get your issues straight, and stop grasping at strange straws.

I do know of one CO incident in Monterey, I look at my log book, I can tell you it was on a Saturday 12 May 1973, the fill was from the Aquarius dive shop, 2040 Del Monte Ave. The problem was that a semi parked next to the building and the truck's exhaust was sucked in through the intake that was mounted under the eve of the roof. No one was hurt, at least permanently.

[Dive-aholic]

I don't know how many compressor complexes you have been responsible for in your lifetime, but just in case it was zero, here are the facts:

• corrosion in a cylinder is caused by water, especially salt water,
• oil in a tank does not mean CO in a tank,
• oil in a tank will slow corrosion.

So please, get your issues straight, and stop grasping at strange straws.

I've owned a couple of compressors. Yes, corrosion occurs through salt water intrusion. There are 2 ways I know of that salt water an get into a cylinder - when the cylinder is emptied and submerged and when the compressor puts it in there. If a compressor is allowing moisture into a cylinder, there are likely to be other issues at hand. Maybe you should think outside of the box.

[cruiser]

I agree that a shop should take responsibility for the air they pump into tanks. However, if they fail in that responsibility, it's my LIFE on the line, and that's a price I'm just not willing to pay.

That's why I'll continue to check my own air.

[Thalassamania]

I've owned a couple of compressors. Yes, corrosion occurs through salt water intrusion. There are 2 ways I know of that salt water an get into a cylinder - when the cylinder is emptied and submerged and when the compressor puts it in there. If a compressor is allowing moisture into a cylinder, there are likely to be other issues at hand. Maybe you should think outside of the box.

Thinking "outside the box" when it comes to simple mechanical devices is generally reffered to as "wishful thinking." CO in a compressor is the result of lubricant ignition or CO being sucked in the intake from another source, water in a tank is the result of entirely different and unrelated failures.

compressor_schematic.jpg

In all compressors the high compression pressures result in high temperature of the discharged air, hot air holds more water than cool air, this must be controlled and is, of course, an important consideration.

Give scuba compressors' rather high discharge pressures are compression is usually done in two or more stages with some method of cooling the air between stages. Aftercoolers or heat exchangers are used used to lower the temperature and to precipitate out as much of the water as possible. While it is quite important to remove water from heated compressed air, especially since water becomes acidic at about 180 degrees, that is entirely irrelevant to the intake of CO or the dieseling of a compressor stage. If there is water in a tank as a result of filling you need to look to the cooling systems and the moisture separators, while if there is CO in the output gas you need to look to the intake, the lubricant, the rings, and compressor overheating.

Now, is it possible for one failure, to cause the other, or to be part of a shared symptomology? CO can cause wet air, but can wet air cause CO? No, wet air can not cause CO, but it can degrade some filtration systems that are in place as backups, note Bauer's recommendation that a CO filter be used in areas where there is a possibility of high CO.

bauer_carbon_monoxide_filtraton_limits.jpg

So what we have here is a situation wherein CO in the compressor output is not a normal byproduct that get "cleaned up" but rather is a symptom of a problem with a compressor that is totally unrelated to the sorts of problems that produce wet air. I believe that wet air can shorten the life of a CO filter system, but such systems should not be relied on anyway since I do not believe that they can be expected to do any better than produce Grade D air.

[Dive-aholic]

You're completely missing my point. If the boat operator was lax enough to allow water through his compressor then he was also likely to not change filters regularly, do oil changes regularly, as well as other issues. I never claimed wet air can cause CO.

[Johnoly]

....but was any of the gas analyzed to definitively rule out CO, or was CO tested in the autopsies. I'm not trying to imply any of those deaths were caused by CO, but unless it was tested for in the cylinder or in the autopsy, we'll never know....

This is a partial answer to your question, but I've pulled copies of many of the autopsy reports for Scuba/RB related deaths in Palm Beach County(PBC), Florida for the last 8-9 years. Full blood workup including CO is always done.

In each tank report, the cylinder in use was sent to a lab for a complete gas and inspection breakdown. The gas is done with a spectrometer and lists everything that is 1ppm or more. It's usually done by Lawrence Factor in Miami Lakes. The usually list O2, CO2, CO, THC, Dew Point, Water Vapor, Oil, Odor, and finally 'unknowns'. It's pretty complete and signed off by 2 people.

I just wanted to add a partial answer to a very big popular diving section of those you listed.

[Thalassamania]

You're completely missing my point. If the boat operator was lax enough to allow water through his compressor then he was also likely to not change filters regularly, do oil changes regularly, as well as other issues. I never claimed wet air can cause CO.

I am not missing any point, you made a claim, got called one it, and now instead of manning up you'd rather weasel. That's a logical fallacy, that you are now backing away from.

Sure, bad maintenance in one area might mean problems in all areas, but it is hardly diagnostic. You're claiming that there are these CO cases in the US based on an internet rumor of a corrosion condemned tank, that if it existed, might have had oil in it and further more, might have had CO in it. If my grandmother, if fact, had two wheels, then she might have been a bicycle. In fact, am I not correct, that the only U.S. CO case you can find is the one I gave you from my log book?