DCI and the perils of diving in a mixed EAN/Air Group

[Bob DBF]

Maybe they were taught to dive by an instructor who had no idea about decompression diving and in a system that traditionally regarded deco diving as voodoo

Instructors now very well might. As for traditional, my initial training covered deco, I don't know when they quit.

Another thing is people often “learn” from how tools work. The term “NDL” sort of implies a no deco dive, being within the no deco limit.

NDL just means there is no limit for a direct ascent to the surface, not that there is no decompression taking place.


It's probably just another victim of "training by catchphrase" that has expanded over the decades.

 

[crofrog]

1. Would you use nitrox on 18m dive? I certainly won't.
2. Is nitrox readily available everywhere? Have you ever been to places where Nitrox 21 is the only gas available?

1. why not?

2. this doesn’t make sense being “qualifed” to breath mixtures greater than 21% doesn’t require you to.

 

[Centrals]

1. why not?

2. this doesn’t make sense being “qualifed” to breath mixtures greater than 21% doesn’t require you to.

The operator you enrolled for OW does not have nitrox!
How did you get certified then?

I have been to many places in Indonesia, Malaysia, Philippines and Thailand, the only gas is Nitrox 21 !!!

 

[Germie]

And I know a number of tech divers with access to O2 who will use 40% for that purpose, instead of 50%, because you don’t have to maintain that tank and reg as O2 clean. The difference in deco time between 40% and 50% is almost negligible, but the maintenance is not.

That is not true, with partial blending, even if you make just a 28% you need to have your tank and valve in oxygenservice (O2 clean and O2 compatible).

 

[Germie]

Give me a break the standards and procedures for the class is, e-learning and quiz, lecture, then analyze 2 cylinders, log them, and program the computer.

That could very easily be included in ow diver training with minimal additional time because most of the information would be tacked onto the physic and philology sections that already exist, and they’d just dive nitrox with the class and do the analysis and logging then.

they finically motivated to perpetuate the status quo. It’s interesting that GUE includes it in REC1. It’s what happens when the focus is on creating safe and comfortable divers versus a guppy mill.

IANTD has a NITROX Open water diver course. So yes, there are agencies where you can do nitrox during your open water course.

 

[Germie]

I have read the whole discussion now.
First, there are also other things that can make that you get dci and the rest of a group not. Dehydration, alcohol, just the form of the day, etc.
But even if you dive within NDL, you can make every dive on a liveaboard (or whatever where) safer without using a lot of extra gas if you come from 20-30m depth: wait 1 minute at 12m, then 1 minute at 9m, then 1 minute at 6m and then do the 3-5 minute safety stop. Go up from the 5m to surface with 1m per minute. If you have to wait till you can use the ladder of the boat, wait at 2-3m depth. Most times this is more relaxing than wait at surface in waves.

 

[Centrals]

IANTD has a NITROX Open water diver course. So yes, there are agencies where you can do nitrox during your open water course.

Different agency has different standards!
No right or wrong.

 

[Celt]

If there wasn’t such a big fuss made about deco the op would most likely have done a short stop on his back gas and not felt under pressure that he’d overstayed the NDL. Now it’s a constant worry will it happen again. As soon as I leave the bottom I think I’m in deco and the only thing that changes ,is the length of time to the surface and what gas I’m going to use.

 

[Centrals]

If there wasn’t such a big fuss made about deco the op would most likely have done a short stop on his back gas and not felt under pressure that he’d overstayed the NDL. Now it’s a constant worry will it happen again. As soon as I leave the bottom I think I’m in deco and the only thing that changes ,is the length of time to the surface and what gas I’m going to use.

1. Will be more careful next time.
2. Read and understand more on deco/ndl etc .
3. Try new sport!!!!!!!