Is nitrox "briefing" enough without certification?

[Snakekid97]

Hi all,

I have a basic OW certificate with about a dozen OW dives. I recently moved to a coastline, but I haven't gone diving in the ocean in about a year (although I have done a couple of quarry dives since). I recently talked to a local PADI instructor/dive charter owner about easing back into things. After scheduling a date to go out on his charter, I found out they only use nitrox on all of their dives. They claim it's the better way to dive. Their website states " If you are not Nitrox certified, don’t worry, we will give you a Nitrox Briefing that lets you dive Nitrox that day...We will also put a _ Dive Computer on your wrist set for 32% so you can track your NDL."

I have read that I should have a certification for nitrox (which I don't have). My question is: would you trust a "Nitrox briefing that lets you dive Nitrox that day" or does this seem to be a questionable practice? I have no prior experience with Nitrox.

I should add, the charter is a 2-tank trip on reefs 40-60' deep over about a 3-hour period.

Thanks!

 

[happy-diver]

Sounds like a fantastic idea

http://www.esaweb.net/e-learning/en-NitroxManual07.pdf

and another fantastic adea

https://diveraid.com/keep-diving/nitrox/

 

[RZomerman]

diving wise underwater there is no difference - it doesn't taste different nor breath different - you will feel clearer in your head (most of the times - although at 30-60' you probably don't even feel the difference) - but you should be aware of the limits imposed - understanding what this does to your body and your dive is "essential" and you will need to learn some ground rules on how this mix is made, how to mark your cylinders and how to analyze, analyze and analyze so you don't end up with 100% o2 at 30m depth.. but the actual dives during the training are.. well.. not that spectacular..

 

[Marie13]

Clearer in the head? Nitrox does NOT counteract narcosis. Only helium does that.

 

[RZomerman]

Clearer in the head? Nitrox does NOT counteract narcosis. Only helium does that.

I've read that newer studies showed that oxygen is not as narcotic as initially thought: Is Oxygen Narcosis A Thing? - but it's probably not as effective as helium.. but at 60' you would not feel any difference whatsoever I guess..

 

[BoltSnap]

I don't get it, why don't you do the e Learning immediately and work with the instructor to get certified also? It isn't difficult or brain surgery and the boat captain is a PADI instructor already.

 

[Wibble]

I've read that newer studies showed that oxygen is not as narcotic as initially thought: Is Oxygen Narcosis A Thing? - but it's probably not as effective as helium.. but at 60' you would not feel any difference whatsoever I guess..

That's the opposite of all the technical teaching we've had that basically states Nitrogen and Oxygen are similarly narcotic, although Oxygen is metabolised.

Nitrox -- increased oxygen in air displacing nitrogen -- gives you longer bottom times, subject to your gas consumption. It also is better for repeat dives as you're not ongassing as much nitrogen.

The Nitrox course is all about knowing that too much oxygen can be lethal. Also how to calculate longer bottom times using tables. The course is not difficult and the takeaway is always analyse and label your gas.

 

[VikingDives]

My question is: would you trust a "Nitrox briefing that lets you dive Nitrox that day" or does this seem to be a questionable practice? I have no prior experience with Nitrox.

Is it safe enough? Probably.

I find the practice questionable, though truthfully you can learn what you need to know about nitrox pretty quickly. The biggest concern for recreational divers is maximum operating depth, which is based on the partial pressure of oxygen in the mix. Partial pressure is calculated by multiplying the atmospheres of pressure by the percentage of oxygen. At 66 feet, the PP02 is (3 ATA x .32) or .96. You don't want to exceed a partial pressure of 1.4.

The reason 32% Nitrox is popular, IMO is that the .32 works out to about 1.6 at 130 feet, so you should never get to the point where you are going to have oxygen toxicity problems if you stay within recreational depths.

One thing I like about SDI is that they don't require you to spend a lot of time using tables in the nitrox course. Tables you'll forget how to use two weeks later...

I agree with the others that suggest that you could do the course prior to showing up, and just take the test and be certified. That would take care of your concerns.

RAID has free eLearning, so you could read their materials to educate yourself before you go, but really the best answer is to just take the course before you dive. Even though you have to use tables, you should be able to finish the PADI course with a little refresher. I'd do the PADIs elearning if it is available, as PADI books are sheer drudgery.

 

[John Bantin]

On a need-to-know basis in keeping with contemporary dive training, a briefing could be "Breathe normally but don't go deeper than (MOD) or you might die!" but how many new divers are told that about air? (MOD 180 feet)

 

[L13]

That's the opposite of all the technical teaching we've had that basically states Nitrogen and Oxygen are similarly narcotic, although Oxygen is metabolised.

That is because previous training was based on older weak scientific evidence. Newer stronger evidence indicates that Oxygen is less narcotic than Nitrogen. How much less narcotic is still unclear, but it is significantly less narcotic.

Nitrox diving is very straight forward. Everything you need to know can be taught in a 5 minute class (or less). It should be part of every AOW class, but that would reduce the revenue from having it as a specialty. @VikingDives 's post above has all the theory you need.

• Know why - trading a shallower MOD for longer NDL, lower N2 loading when flying after diving
• Know your MOD - as @John Bantin said, even air has a MOD
• Know your gas - proper analysis and labeling
• Set your computer - check every time, if table diving use the right table