Nitrox or Rescue Certification

[TMHeimer]

I may have said this, but I don't think one has to do with the other. I think everyone should do Rescue for safety's sake and Nitrox for extended bottom time--not related (unless you split hairs). If you are comfortable with your diving, take Rescue.
You can take Nitrox anytime. A factor of course is when either is available at your LDS.

 

[Damselfish]

Then, as a divemaster if you wanna go pro, nitrox is still a really nice option to have when you have a full morning of try dive and don't wanna use a 15L tank because it destroys the back

Don't understand what Nitrox has to do with the size of the tank?

 

[Nianne]

You use a little less air with nitrox. Something between 5 and 10%. Less air, smaller tank.

 

[boulderjohn]

You use a little less air with nitrox. Something between 5 and 10%. Less air, smaller tank.

I never heard this before. Why would you use less air?

 

[guruboy]

You use a little less air with nitrox. Something between 5 and 10%. Less air, smaller tank.

Where did you learn that?

 

[Damselfish]

You use a little less air with nitrox. Something between 5 and 10%. Less air, smaller tank.

no, you don't. Urban myth that occasionally comes up. (And even if you did, the jump down to the next smaller tank - if even available in a place - will probably be much more than 5-10%.)

 

[TMHeimer]

I too haven't hear of the less air thing. When you are very deep (on whatever gas), you are getting more O2 with each breath--more than you need since you get what you need at the surface. And you HAVE TO fully use your lungs (not sure why and don't think the reason really matters)--ei. apparently you can't just take smaller breaths because the air at depth has more 02 and you only need what you need topside. This is what leads to 02 hits if too deep on Nitrox (or maybe below 180' on Air).

Re Rescue: I did it with 26 dives beforehand. Went OK. Somethings I did great on, others not so great. But I got the knowledge. So unless you are still uncomfortable with the basics I advise to take it as soon as possible--in case something happens in the mean time, which can occur especially if two newer divers are buddying up.

 

[Gary_Ward]

Nitrox or Rescue? That's a no brainer for a new diver. One will increase your bottom time (if no deco-limits are your issue), whilst the other will make you a better diver... All the usual caveats apply (crap instructor, crap course, but that goes for both).

When I am asked about Enriched Air I always ask the divers where are they planning to dive and how are they planning to dive. If you're planning on diving with a dive operator in a group of divers, and on a schedule of 2-3 dives per day when you're on vacation... save your money and don't bother with Nitrox! Most dive operations cater for a lowest common denominator in a group or have a schedule. So whilst with a good blend you might be able to get a bottom time of 3 hours, you won't actually have the time or the gas. If you're planning on doing livaboards/trips with much more diving, then hell yeah - hit that Nitrox as you'll feel the benefit in the shorter surface intervals and be less fatigued.

Rescue diver is my favourite course to teach! You're able to have so much fun with the students and the DM's and really push hard. In my view Rescue is a course that should be completed by every diver! Open Water is great, it gets you focused on you. Your air, your mask, your safety. Advanced gets you focused on you in your environment (night/deep etc) or you and equipment (photography, S&R etc). Rescue is the first course you'll encounter which starts to get you to focus on others. Completing the course with an instructor who loves teaching rescue, and you will become a much safer and more aware diver.

 

[Gary_Ward]

You use a little less air with nitrox. Something between 5 and 10%. Less air, smaller tank.

Utter poppy-cock! I hear this all the time from new divers who do not understand what enriched air does or how it works... Let me explain a little (for those who might need it).

If you're diving on air and you breathe through a 12l/80cuft tank in 30 minutes at a given depth - lets call it 18m/60ft. Your gas consumption will be 80l/minute. If you substituted that tank for one with 32% nitrox, you would still breathe that gas at 80l/minute and it would still last you ONLY 30 minutes. Enriched Air Nitrox is a gas just like air, its not thicker and you don't suddenly start breathing less. Your lungs still need to fill and empty to the same level they did on air.

As you improve your air consumption (i.e. you can go a lot longer than 54 minutes at 18m/60ft), then you might want to switch to enriched air, as this will increase your no-decompression stop limits - what this means is that if you have the gas left in your tank (and are not too fricken cold already) you can safely dive longer without the risk of nitrogen over-saturation.

Of course its not all brilliant positives. There is a kicker with using Nitrox too. You're increasing your risk to Oxygen Toxicity and shallow water blackout - both of which tend to be fatal. This means you can not dive as deep, need to manage your depth dependent on your blend and must must must manage your assents. Runaway assents from that wreck at 100ft could be a bit nasty!

On the plus side, diving with enriched air reduces fatigue associated with diving (if you're diving lots), but so too does getting fitter.

 

[guruboy]

technically, I think enriched air is actually more dense since there is more O2 and O2 is denser than both "plain air" and Nitrogen.