The Beginner's Mixture

[ZenDiver.3D]

Bailout.

Definitely, when in doubt........

 

[ZenDiver.3D]

Depending on the location I think it would be a positive addition.

Starting with hard bottom sites would be a requirement of course. So, the new diver starts up inhaling a full bottle in a blink of an eye so for the very first few dives probably it makes no difference, but knowing that you have a lot of minutes before a deco obligation sits better in your mind than only having a few minutes left. This factor would reduce the amount of immediate things to worry about.
Then as the divers chill a little and their gas consumption gets better, it allows additional bottom time to work on their skills longer and truly enjoy their dives.

The few times I end up doing shallow dives with plain air, aggravates me to no end having to come to the surface before getting cold with tons of air left in the tank.

Wow... So you do those 200 minute NDL's with one tank of ean? And the new diver should not run into deco obligations. Their limit is 18 meters and most of those dive 12 meters and above. hundreds of minutes- one tank. Ean or air would not matter... They are out in less than an hour anyway.

 

[DCBC]

Such as?

Some of the benefits of Nitrox include:

1. Elimination of narcosis;
1. Longer no decompression limits;
2. Reduced decompression penalties;
3. Shorter surface intervals;
4. Faster off-gassing than air during decompression (which is what I mainly use it for);
5. For many it lowers your gas consumption; and
6. In theory, the effects of a barotrauma may be reduced, due to the improved circulation of breathing enriched air.

On the other hand there are:

1. Equipment cleaning considerations (increased cost of maintenance);
2. Reduced number of facilities (at present) that can provide fills;
3. Increased risk of oxygen toxicity if you break the rules (dive too deep);
4. Reduced time of total breathing exposure;
5. With the increased dive times, cold and dehydration may be predisposing factors.

 

[sabbath999]

I think that it is remotely possible that rebreather technology might become cheap enough for the serious to average diver to buy one.

You taunt me with your sexy words.

 

[sabbath999]

Some of the benefits of Nitrox include:

1. Elimination of narcosis;

We were taught in our Nitrox class (PADI) that oxygen has roughly the same narcotic effect as nitrogen, so we were to figure that oxygen enrichments was a wash when it comes to being narked.

Was PADI telling a fib?

 

[muddiver]

Bailout.

My preference for bailout would be EAN21. You can still use it as an emergency breathing gas down to around 218 fsw. Where as with most other Nitrox mixes the MOD would be much shallower than that. So why use Nitrox for a bailout gas?

 

[muddiver]

Some of the benefits of Nitrox include:

1. Elimination of narcosis

Sorry, I don't buy that one. How can you eliminate the effect of a chemical (i.e. Nitrogen) if the gas is still in the mix? We are discussing Nitrox, right? Not Heliox? There is also no proof of this commonly stated theoretical benifit.

 

[JeffG]

Some of the benefits of Nitrox include:

1. Elimination of narcosis;

Nope

1. Longer no decompression limits;
2. Reduced decompression penalties;
3. Shorter surface intervals;
4. Faster off-gassing than air during decompression (which is what I mainly use it for);
5. For many it lowers your gas consumption; and
6. In theory, the effects of a barotrauma may be reduced, due to the improved circulation of breathing enriched air.

and which of these are safety advantages? Especially at "shallow depths" for beginner divers? Where the air consumption and/or water temperature has a bigger bearing on dive times.

On the other hand there are:

1. Equipment cleaning considerations (increased cost of maintenance);
2. Reduced number of facilities (at present) that can provide fills;
3. Increased risk of oxygen toxicity if you break the rules (dive too deep);
4. Reduced time of total breathing exposure;
5. With the increased dive times, cold and dehydration may be predisposing factors.

So..some minor advantages that rarely come into play in exchange for a danger that could kill you.

Sounds like a beginners gas to me.

 

[muddiver]

We were taught in our Nitrox class (PADI) that oxygen has roughly the same narcotic effect as nitrogen, so we were to figure that oxygen enrichments was a wash when it comes to being narked.

Was PADI telling a fib?

Yes, otherwise Helium and Oxygen mixtures for deeper diving would not remove the effect of Nitrogen narcosis.

 

[rstofer]

The brand new diver consumes so much air that they can't approach the NDLs on dives for which they are qualified (60' or less). So, at best, Nitrox gives them a reduced SIT and reduced nitrogen loading. Good things, or course, but it won't increase bottom time.

When diving with buddies that use Nitrox, the Air diver will very likely limit bottom time and SIT. As a result, there is pressure to get on board. No reason not to...

So take the course and learn what its all about.

Richard