Deep Diver vs. Deep Air Diver

[BStewart26]

I have been looking around an trying to find an answer to this question and have yet to find a definite answer. Any help would be appreciated.

I am currently an IANTD AOW diver and Nitrox diver. As in most AOW certification I have been certified deep diver to 100fsw. I have been looking though and noticed that IANTD offers a deep air diver course. What is the difference in deep diver and deep air diver. Through research, the conclusion, I have come to is that Deep air is an intro into tech diving with emphasis on decompression using nitrox up to 40%. In AOW we never really went in depth about deco, just avoid it if possible. Is this the main difference between the two it is just more in depth?

 

[DA Aquamaster]

I can't speak to IANTD but I can say that TDI offers a advanced Nitrox and Deco Procedures courses and when combined they provide certification to 150 ft on air (or a suitable nitrox mix like 26%.) Advanced nitrox is designed to use deco mixes up to 100%. 50% is very common on short run time dives as you can switch to it at 70' where it gets you out of the water fairly fast with most VPM or gradient models using deep stops. 100% works well as an additional gas on longer or deeper dives as it shortens the time at the 10' and 20' stops. More importantly using two gases allows more flexibility in terms of lost gas contingency planning on longer dives where deco on your reserve backgas alone may not be adequate. Contingency planning takes into account the potential to lose or be unable to access one deco gas, so two gasses gives you more options.

Personally, as for the use of 40%, I would not bother - it sounds like a work around to avoid having to take advanced nitrox.

TDI also offers extended range once you have completed the two previous courses. That will certify you to 180' on air, but more importantly (and a lot more usefully) you can also add normoxic trimix to the course to certify you to 200' on trimix. Then later on you can take an advanced hypoxic trimix course certifying you to 300' if you feel the need.

As you go below 130' ft deco obligations accrue very quickly and gas planning becomes much more of an issue both at depth and in term sof meeting the deco obligation, plus when in deco you are in an overhead situation where you do not have immediate access to the surface so 100% redundancy is required in terms of equipment. So any deep air course needs to address all three areas. An advanced nitrox course allowing the use of high percentage deco mixes will get you out of the water a lot faster, so I would not bother with any deep air course or series of courses that did not provide that training.

 

[Blackwood]

I'm not sure you'll be able to find someone who still teaches IANTD Deep Air and there wouldn't be much of a reason to take it unless you are geographically removed from trimix and have a need to dive deep.

Note that the Deep Diver course isn't "technical". It extends to 130 feet, though it may be taught in doubles, etc..

 

[DA Aquamaster]

Ah...the deep air versus trimix debate...

Let's just summarize it and skip it

1. Deep air used to be the only game in town and divers seem to accomplish amazing things on air

2. Some of those divers also died

3. Trimix is the current choice of most deep divers, and they do amazing things with it.

4. Some of those divers still die.

5. Some trimix divers go to the extreme in terms of what they consider to be an acceptable END (30/30, etc).

5. Those divers ar at odds with the other extreme who don't pop a gasket at the thought of doing 150-170' on air - if the conditions are right, and if they perform well at those END's -

6. A divers' tolerance of narcosis varies from diver to diver and day to day. One of the concepts underlying deep air training is to help the diver recognize their limits at any END.

7. In addition to availability issues, trimix is expensive (and getting hideously expensive) and it ties up your tanks when your dive gets blown out and/or you end up using a very expensive trimix fill on a much shallower inshore dive. OC trimix means owning several sets of doubles if you really want to dive with the right gas.

8. Others will argue the cost of He is minimal in comparision to the travel, hotel, boat fees, etc, but every bit hurts the wallet and if diving trimix means diving less it may not be a great thing in terms of promoting proficiency.

9. Rebreathers are probably the future of trimix diving as it reduces the amount of He used ten fold and the rebreather allows you to maximize PPO2 to minimize deco, making deeper diving a more affordable and less logistically challenging endeavor.

10. #9 obviously leads to the OC versus rebreather debate....

Personally I am middle of the road. There are dives in the 100-130' range that I would not want to waste helium on as they are not so challenging that they could not be done safely on air. There are also dives in the 130-150' range that I would only do on trimix and below 150', I am outside my comfort zone on air and would only use trimix.

As stated above, the TDI approach lets you do extended range and normoxic trimix together and you get a feel for both. Then you can make your own decision as to what you want to use in a given situation.

And eventually, I will probably end up with a rebreather.

 

[knotical]

IDA also has a Deep Air course. International Divers Association - IDA World Wide
I'd consider taking it to help decide how deep I might chase a diver in distress.

 

[Tomeck]

Ah...the deep air versus trimix debate...

Let's just summarize it and skip it

1. Deep air used to be the only game in town and divers seem to accomplish amazing things on air

2. Some of those divers also died

3. Trimix is the current choice of most deep divers, and they do amazing things with it.

4. Some of those divers still die.

5. Some trimix divers go to the extreme in terms of what they consider to be an acceptable END (30/30, etc).

5. Those divers ar at odds with the other extreme who don't pop a gasket at the thought of doing 150-170' on air - if the conditions are right, and if they perform well at those END's -

6. A divers' tolerance of narcosis varies from diver to diver and day to day. One of the concepts underlying deep air training is to help the diver recognize their limits at any END.

7. In addition to availability issues, trimix is expensive (and getting hideously expensive) and it ties up your tanks when your dive gets blown out and/or you end up using a very expensive trimix fill on a much shallower inshore dive. OC trimix means owning several sets of doubles if you really want to dive with the right gas.

8. Others will argue the cost of He is minimal in comparision to the travel, hotel, boat fees, etc, but every bit hurts the wallet and if diving trimix means diving less it may not be a great thing in terms of promoting proficiency.

9. Rebreathers are probably the future of trimix diving as it reduces the amount of He used ten fold and the rebreather allows you to maximize PPO2 to minimize deco, making deeper diving a more affordable and less logistically challenging endeavor.

10. #9 obviously leads to the OC versus rebreather debate....

Personally I am middle of the road. There are dives in the 100-130' range that I would not want to waste helium on as they are not so challenging that they could not be done safely on air. There are also dives in the 130-150' range that I would only do on trimix and below 150', I am outside my comfort zone on air and would only use trimix.

As stated above, the TDI approach lets you do extended range and normoxic trimix together and you get a feel for both. Then you can make your own decision as to what you want to use in a given situation.

And eventually, I will probably end up with a rebreather.

It is well wittren, but I think a rebreather is more dangerous than deep air, if there are more rebreather accidents than deep air.

 

[BStewart26]

I appreciate the clarification. I never though of the deep air as being an old course but it makes sense because trimix in the rec world from what I understand is fairly new. The only reason I considered taking Deep air was because where I live if you want to make it past 120ft you need a shovel or have to take an extended boat ride out about 50 miles to maybe reach 200ft and currently none of our dive charters even go any deeper than maybe 115ft . I would have to travel to take either deep air or trimix so it sounds as though trimix may be a better choice as I would like to take some diving trips and do some deeper diving. For right now I am just going to work on getting the Adv Nitrox and work from there.

 

[Blackwood]

If you are unlikely to ever make it much deeper than 120, Trimix seems an expensive luxury.

 

[BStewart26]

Ok well I have a two new questions now. One do you have to obtain a trimix certification to dive helium on rebreather? And two would it be more beneficial to take a rebreather or trimix course? I am able to dive deeper depths I would just have travel a little. I do plan on doing deeper diving. We do have some deeper dives like the Oriskany which is max depth to about 210ft. So I can benefit by having a trimix cert.

 

[sunkmail]

It is well wittren, but I think a rebreather is more dangerous than deep air, if there are more rebreather accidents than deep air.

Please state your source.


What rebreather did you train on?
What certification agency did you go thorough? Did they teach you to use and maintain your equipment properly? Did you practice safety/emergency drills?

What in particular did you learn that made you decide that it wasn't safe?

Were their any professional lessons or research involved in making this opinion?

I'm not saying that CCR is the only way to go. I'm not trying to open the rebreather Vs. non-Rebreather discussion, but please:

Don't make blanket statements like that!

Dive air if you like. only dive 32% if you like (etc). Whatever you are comfortable with is what you should be using. (as long as you have the proper training to use it)

------------

To the OP -

Many areas offer a rebreather experience day - go, learn, try them out (many different ones usually), Then, make the choice that is right for you, based on your own research.

Opinions on SB are great. I've used them a lot in my own research, just watch out for unsupported information and statements.

If you haven't already, join rebreatherworld.com - Between there (RBW) and here (SB) there is so much you can learn.

You may have noticed, I haven't stated my own set-up. That was on purpose. (If you are interested, message me, I'll share.)

My OPINION: You are heading into tech territory. Things are going to get expensive, more complicated, and require more dedication to your dive planning, execution, and gear maintenance. Each path has some easy aspects and some difficult. Only you can choose which to go with.

In Diving, as in the rest of life, there is no one 'Right' way.