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So I have been to the classes, but I am not a gas blender. Today I was diving and noticed a funny taste in the gas, almost like an oily taste. I checked the gas befor ethe dive and they read right at 32% o2. I felt fine but still turned the dive after I noticed the funny taste. My question is, at what point do you folks ignore a "funny" taste?
Never! Why would you ever ignore something that didn't seem right? This goes for any type of diving, but especially in the overhead.
I have turned a few dives due to funny taste. Better safe then dead. I wouldn't enjoy the dive wondering if I was going to die any minute.
Read this thread, it'll scare the **** out of you http://thedecostop.com/forums/showthread.php?t=46914
Turn the dive if you have any thoughts that the gas is tainted.
As soon as I taste something funny I'm turning it. Like the others have said..... better safe than dead.
Turn the dive immediately. If you can taste your gas, somethings wrong. Might not be a bad idea to look in the tank either. Better to be safe than sorry.Quote:
Originally Posted by adam0321
I turned a dive early during descent off Puerto Rico while conducting a science dive in the late 1980's. My gas had an oily taste and I figured it might be my last. I signaled my two buddies I was heading back and they continued down to about 60'. On the boat was our new DSO, who previously worked as a Russian commercial diver. I couldn't taste the oil on the surface, but had no trouble at depth. He interrogated me later and questioned my experience and diving competency. The ******, he probably filled the cylinder while one of the field station's trucks was running nearby.
I gotta say, after getting into tech diving I'm not all that impressed with "science" divers. I was diving off the M/V Spree in the Dry Tortugas a few years ago with some NOAA divers. On two separate occasions I thumbed a dive on gas, which my buddy acknowledged by wagging his finger "no". Funny, I've never seen those signals exchanged in a cave.
Dave
I ignored a "funny" taste in my gas on a dive once and never since. I knew that something was a bit off while descending from the taste of the air but decided to ignore it. After a few minutes at 120-130' I started having visual & auditory disturbances, tongue/throat went numb, etc. Thankfully it was an OW dive and I had a very familiar buddy + had a buddy bottle on me. I checked the tank after getting to the surface and smelled a very strong chemical odor in the air. Come to find out the guy I borrowed the tank from had used LocTite to make sure that pesky dip tube wouldn't unscrew itself ever again and then immediately filled the tank - I did the first dive on the tank. We had a very serious discussion about it when I returned the tank.
I should have checked the tank prior to the dive and never hit the water.
Never ignore anything that seems to be wrong. A few months ago I was on a solo dive, the gas in both tanks read the same and were filled from the same station. When I switched from my right tank to my left tank it tasted different and I felt clouded after about a minute. I got back on my right tank and everything cleared up and I felt better. I exited on right tank with no problems. I checked the gas on both tanks when I got out of the water and the both read the same. I went ahead and broke down both tanks and found the left tank was contaminated. I cleaned both tanks and have had no problems since. As others have wisely said, better safe than dead. Live to dive another day.
Quote:
Originally Posted by adam0321
@ben - What were they contaminated with?Quote:
Originally Posted by benjamin
@adam - Have you followed up with your tanks?
I would assume dumping, visual, and cleaning would be minimum. Does anyone have any other analysis done, esp. if the source of gas is suspected?
I am curious as well about any followup...
I don't mind wrapping up a dive early... or skipping one altogether. It's just a dive.
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I always do a taste and smell predive check. In the cave, i would never ignore and always thumb the dive. Also i would switch gas sources. If solo, to the buddy bottle, if teamed, then to a stage bottle, and if nothing else is available i would indicate ooa to my buddy. It is this last part i had not really thought about...guess i missed that and not sure about hand signals maybe the narcosis dizzy signal? Bad gas can influence decision making skills rapidly.
So would everyone also bail out of suspected bad gas even to your buddy? I would imagine this is in the training standards somewhere and i just need some recurrent training. So here is my proposed buddy and no other gas source emergency procedure: flash, hand signal problem, hand signal dizzy, thumb, observe returned thumb, signal ooa, once stable, ok, look for returned ok, exit. Maybe just flashing and doing the ooa immediately would be better? Of course if teamed up with sufficient and credible stage gas, switch to stage, flash, thumb. If solo switch gas and exit.
An oily taste that starts at 40-60 feet and gets worse as depth increases is ALWAYS bad air. Deploy thumb and go back to the parking lot. Had it happen twice, the first time I blew it off and felt sick as a dog for two days. The second time I turned around. Emptied the tanks and refilled and went on with the diving. I should have removed the valves and checked the tanks, but hind sight is always 20-20.
Neither tank smelled or tasted odd at the surface. Inside of left tank was contaminated. (Problem was at fill station and fixed on their end. Fill station wasn't in Florida, I'll see if I can get a copy of their report and post it if I can). I tumbled and 02 cleaned both tanks and have repeated same process twice for my own peace of mind since the incident. Haven't had any problems since.Quote:
Originally Posted by scububa
Turn immediately upon getting the funny taste.
A few months ago I picked up one of those Analox CO testers. So far every tank I have checked has been 100% OK with not the slightest trace of CO, but if I get a bad tank and it is the type of thing that this little gem will discover I wouldn't even get near the water with it. Contaminated gas is just a game of roulette I don't want to play.
we already have a hand signal for this....out of gas. doesn't matter if it's bad tasting or none at all, the sign means "give me your regulator now." no need to explain why.
skip
Carbon Monoxide (CO) is odorless, colorless and tasteless. Bad taste or odor probably is coming from hydrocarbon (read compressor oil) vapor in the gas.Quote:
Originally Posted by Mark Vlahos
IF... a tank contaminated with hydrocarbon is stored for a time, there "should" be some CO generated within the tank. But a FRESH tank, just filled today could have hydrocarbon contamination without CO being present.
Sure, anything is possible. The CO tester is not a panacea, but if it spots a bad fill I will be better off for it.Quote:
Originally Posted by gschaut
+1 on predive taste and smell of very tank - and don't forget your 02 bottle. The only time I've ever had an issue underwater occured when I switched to 02 @ 19 ft and was hit full force with the overwhelming smell of chlorine in the gas. Turns out the plastic seat in the Thermo valve had been vaporized by a too-rapid fill. I (and everybody around) was damn lucky it didn't go KA-BOOM during the fill. Lesson learned - ALWAYS taste and smell EVERY gas predive. Ps - when we took the valve apart, the only thing left of the seat was a smudge of carbon. Amazing it didn't blow up.Quote:
Originally Posted by wingman
Adam,
Where(ish) were your fills? I got bad 32% Nitrox fills in PCB two weeks ago and the taste is still lingering so I might have to get 'em cleaned. I alerted the shop and they were good and helpful about taking care of it and giving me free re-fills when I was over there yesterday. A few people think it might have been "oil that got past the filter."
I took the bad fills to CE by Peacock Springs and they drained the tanks and looked inside; everything looked clean. The taste still lingers though, very subtly.