Nekton boats may come back!!

[tarponchik]

Not sure why you say max depth is easier to controll than time under water.

Beacause (a) lots of places people dive at simply are not deep enough and (b) it is quite easy to set alarm at the known depth limit. Also, divers constantly get idea of depth not only from looking at the gear but from various secondary signs, like how deep other divers are, abundancy of life etc.

 

[diverdoug1]

Beacause (a) lots of places people dive at simply are not deep enough and (b) it is quite easy to set alarm at the known depth limit. Also, divers constantly get idea of depth not only from looking at the gear but from various secondary signs, like how deep other divers are, abundancy of life etc.

If a diver can not pay attention to the alarm announcing he is going into deco, I doubt he will pay attention to a maximum depth alarm!!!

 

[daniel1948]

Max depth which is causing oxygen toxicity is much easier to control than total time underwater, or total time at max depth, or the ascending rate.

Is it really??? BOTH are a matter (I'd say a simple matter) of looking at your gauges. Honestly, the ONLY way I can tell my depth is to look at my gauge. I certainly cannot tell the difference between 100 feet and 115 feet just by the fishes or the ambient light. In fact, I'd argue that it might be EASIER to inadvertently drop below MOD than to exceed no-deco time. (Which is why I set my own max depth 5 or 10 feet above 1.4 bar ppo2.) So nitrox might be more dangerous for a careless diver who does not pay attention.

I often see divers going deeper than me. Sometimes it's a newbie who's not paying attention, and whose diving career is likely to be cut short if he doesn't learn quick. Sometimes it's an experienced diver who has chosen to dive a different profile than I am diving. In either case, I cannot rely on that diver to clue me in as to my own depth.

... Giving nitrox to a diver unable to manage a dive profile will not mitigate thier overall risk, and is NOT a good idea.

I agree 100%. But I'd go further: Giving a scuba tank to a diver who is unable to manage his dive profile is a very bad idea, and likely to result in death or injury. A diver who cannot dive safely on air should not be given nitrox: he should be kept out of the water.

The whole point of certification is that we're supposed to learn how to dive safely, and that means, among other things, knowing and staying within the safe limits of the gas we have in our tank.

Saying that nitrox is safer than air is like saying that a hammer is a better tool than a screwdriver. One is not better than the other. They are different tools used for different tasks. I like to dive nitrox because it suits the kind of diving I like.

 

[tarponchik]

Saying that nitrox is safer than air is like saying that a hammer is a better tool than a screwdriver. One is not better than the other. They are different tools used for different tasks. I like to dive nitrox because it suits the kind of diving I like.

I did not say "better", I said safer. And a hammer should be compared with a similar tool, like a sledgehammer, not with a screwdriver. My comparison with alcohol fits better here. Though, in theory, folks who can't hold their liquor should not be given alcohol in any form, most governments place tougher controls on hard liquor than on beer/wine sales. You can argue whatever you want, but since the stats show that DCS is more frequent than oxygen poisoning, then yes, nitrox will make diving safer.

Another analogy is the seatbelts. Most countries enforce using of seatbelts now because seatbelts save lives of car occupants. However, since seatbelts were introduced the number of pedestrian fatalities started to grow because the drivers felt safer and became more careless. You would probably say, quite rightly, that folks who can't control their speed should not be given driver's licenses in the 1st place. But the governments all over the world simply go for the lesser of the evils and enforce the seatbelt use because pedestrians fatalities are only a small fraction of total fatalities on the roads.

 

[daniel1948]

And I say that comparing air and nitrox is like comparing hammers to screwdrivers because they are different tools used for different tasks, even though hammers and screwdrivers are both used in construction, and air and nitrox are both used in diving.

Further, maybe DCS is more common than ox tox because more people dive on air than on nitrox.

According to PADI, nitrox is not "safer" than air, provided that each is used properly. A diver unable to dive safely on air will not dive safely on nitrox, even if he does have more no-deco time.

 

[tarponchik]

According to PADI, nitrox is not "safer" than air, provided that each is used properly. A diver unable to dive safely on air will not dive safely on nitrox, even if he does have more no-deco time.

I won't argue with the 1st statement here, but the 2nd statement should rather look like "since some fraction of divers will be reckless anyway, and since they are more likely to get DCS when diving on air than oxygen narcosis when diving on nitrox, putting these drivers on nitrox will probably reduce the negative consequences of their recklessness."

 

[gregpsych]

I just found out they closed down--My wife and I were on the boat a couple of years ago and had planned to go again--refit it and we will be there!!m

 

[daniel1948]

I won't argue with the 1st statement here, but the 2nd statement should rather look like "since some fraction of divers will be reckless anyway, and since they are more likely to get DCS when diving on air than oxygen narcosis when diving on nitrox, putting these drivers on nitrox will probably reduce the negative consequences of their recklessness."

So, would you give them nitrox without requiring them to be certified first in its use? What would you do about divers who refuse to take the certification class? Would you require everyone to pay the extra $10 per tank? Or would you require dive shops to provide it at no extra charge?

What about divers who don't want to dive nitrox? What about divers who want to dive in the 107 - 130 foot range? (Below the MOD for EAN32.)

So maybe you just want to make it available to anyone who wants it and is properly certified for its use. Would you prohibit dive shops from operating unless they have nitrox equipment? Would you have the governments of small islands pay the $10 per tank, or would you regulate the prices so that divers using air paid extra so that nitrox divers would not be paying extra, in order to encourage reckless divers to use the more expensive gas?

Or maybe you'd just have PADI and the other agencies change their recommendation, ignore their own research, contradict their own science, and say that nitrox is safer and recommend that divers become certified and use it, placing your perception above their own studies?

And please note that even if your statement above is correct, is does not mean that nitrox is safer, because most DCS hits are non-fatal, whereas most oxygen toxicity hits are fatal. You might end up having fewer incidents but more deaths! In fact, the reason nitrox requires an additional certification is that it presents additional safety issues. A diver who will not monitor his no-deco time, and ends up with DCS probably won't test his gas either. It takes more time to test your gas than it takes to glance at your computer.

In sum, I think you are relying on anecdotal, rather than scientific evidence, and misinterpreting even that.

(And I presume you meant to type "oxygen toxicity" when you wrote "oxygen narcosis," because the danger from oxygen-enriched gas is toxicity. Narcosis comes from nitrogen, as much as from oxygen if not more so. To avoid narcosis you have to use a helium mixture. But that requires a lot more training than nitrox, and is more expensive.)

Of course none of this has anything to do with the thread topic. But what the hey! The original thread topic is dead anyway.

 

[gregpsych]

Do the Bahamas with departure from Ft. lauderdale. No reason to do a liveaboard in Cozumel--much rather stay at a nice all inclusive10 min from the reefs and then party at night

 

[Chuckitall]

so what's happening. Everything else seems way off subject. If Deep can give us an update or tell us not going to happen.