Deep Diving without Nitrox

[Bubble Junky]

The following is a quote from Page 6 of the PADI Instructor Training Bulletin for Second Quarter 2006




Enriched Air Diver Course Dives No Longer Required!

"April 7, 2006.....



Since the PADI Enriched Air Diver course was first introduced, enriched air diving has become more popular with more widespread reputable enriched air providers. Some who teach the course have requested a reevaluation of whether or not dives should be mandatory for course certification. As a result, effective immediately, the PADI Enriched Air Diver course no longer requires dives, though they are still recommended. Instead, a pre-dive simulation is required. The critical objectives of the Enriched Air Diver course are both learned and applied out of the water, and center around the physical procedures of gas analysis (and related use of logs and contents stickers). The performance requirement for the dive can effectively be addressed in a pre-dive simulation, which can be presented in conjunction with practical application 1 and 2.

The performance requirements for this simulation are listed below:

1. Demonstrate pre-dive equipment setup, blend analysis label confirmation for two enriched air dives with two different scuba cylinders fill with EAN.
2. Plan two enriched air dives including maximum depths, oxygen limits and no stop limits using the RDP, the DSAT Equivalent Air Depth and Oxygen Exposure Tables and the Enriched Air RDP's, based on: depths, times, gas supply and surface intervals. Provided by the instructor and the analyzed content of the two scuba cylinders filled with enriched air."

Cheers - sorry, still not received mine.

 

[greg454]

Thanks for the explanations, guys. Now I get it. With nitrox, instead of spending 8 minutes at the bottom, you can double or triple that time. I'll take that class eventually.

 

[rawls]

PADI may no longer require the dives for the enriched air course, but that doesn't mean the PADI instructor does. My DM instructor still requires students to do 2 checkout dives with enriched air. So I think alot depends on the particular instructor.

 

[Dustinh]

I think that the dives not being required is a shame. Dive training and dive experiance are not mutually exclusive, they should go hand in hand. What's next, an open water course with no pool time or dive time? I think it's a mistake...

 

[Hoyden]

Until you are limited by NDLs instead of air comsumption, Nitrox is a luxury. When you reach that point, it is a good investment, especially if you are paying for boat dives.

Jackie

 

[Zeeman]

I decided to get my Nitrox cert because I found that my breathing was good enough that it was my NDL's limiting my dives, and not my air...

As others have said, Nitrox isn't for deep, it's for long

Z...

 

[The Kraken]

Greg,

Another thing to consider is the tank you're diving.

For kicks and giggles I've developed a matrix that gives dive times based on SAC rates relative to different tank volumes.

Here's one example:

Based on a new diver with a SAC rate of .6 cfm diving an Aluminum 80 and maintaining a 500 psi reserve:

At a depth of 75 feet, the diver will have approximately 33 minutes of breathing gas.
The NDL for this dive on air (21% O2) is approximately 35 minutes.

Doing the same dive using EAN36 as breathing gas, the diver will have an NDL of 65 minutes but, alas, will still be limited to a bottom time of 33 minutes due to the volume of the tank.

Using a 120 cf tank would provide the diver with a bottom time of 52 minutes. Still not getting the max bottom time, but significantly increasing his bottom time.

So you can see that in many cases, the volume of the tank is going to be the limiting factor in getting the optimum benefit of nitrox diving.

the K

 

[DandyDon]

Thanks for the explanations, guys. Now I get it. With nitrox, instead of spending 8 minutes at the bottom, you can double or triple that time. I'll take that class eventually.

Well, no - not double or triple. About 50% more bottom time at depth, like the popular Florida Keys wrecks. If you were diving air on one of these, I wouldn't want to be your bud and come up when you needed to.

And like the redheaded lady said, it's even more important on repetitive dives, like back to back dives to 110 ft on NC wrecks, or liveaboards.

Keep the course on your short list and do it as soon as you can...

 

[ocrmaster]

Nitrox

Advantages: Shorter STI and Longer NDL.
Max. depth is still 100 FT, unless you take Deep Certification.

Base on the percentage of O2 you will be taught to calculate your MOD - Max. Operating Depth.

Good Luck!

 

[Somethin-Fishey]

Until you are limited by NDLs instead of air comsumption, Nitrox is a luxury. When you reach that point, it is a good investment, especially if you are paying for boat dives.

Jackie

Even if air limits you on the first dive...the second, third and fourth dives of the day are really gonna shine with nitrox. Arond here we spearfish alot and will start in 110' and move around and end up in 75ish for the last dive. People on air usually can't even make the fourth dive, where I still have 40 minutes at 75' and I don't feel like someone beat me with a stick. I also use Steel 120's for the first 2 dives and Al 80's on my last 2, just because that is what I have, but I am still normally limited by NDL rather than air

Nitrox is best if you never go below 110-120ft, make repetitive dives in one day. It will extend your bottom times on subsequent dives and/or shorten your surface interval.