Does it make any sense to dive with Nitrox for shallow dives?

[Chebby]

Quick qestion for you all, sorry if this is in the wrong forum:

Does it make any sense to dive with Nitrox for shallow dives? If 90% of my dives are to 60 feet and less, do I really need Nitrox? So far I am OW and perfectly fine using air, but I am curious. Is that mostly for deeper dives? I've been told, it's only 100 dollars to get certified, but If I don't really need it, that's 100 dollars I could have spent on something else, right? (like my cell phone bill )

 

[Tassie_Rohan]

If you're only doing 1-2 shallow dives a day then you don’t really need nitrox - above 60 ft your bottom time is going to be limited by your air consumption rather than the no decompression limits. Nitrox can be handy if you're doing 3-5 shallow dives a day (such as on a liveaboard): you get a bit more time in the later dives, have bit more of a safety margin and may even feel a bit less pooped at days end.

If I had to decide between spending money on either more frivolous diving paraphernalia or some essential item (bills, rent, food, etc) the diving would always win hands down - so I can’t really help you with your decision…

Safe Diving,
Rohan.

 

[mike_s]

Exactly what "Tassie Rohan" said. It will add a small safety margin and you won't be as "pooped" at the end of the day.

Since your air consumption is the same, unless you have bigger tanks, you won't stay down any longer, it just gives you better NDL (No decompression limits). It's main benifit is for repetitive dives daily, like on a liveaboard (which is the reason I took the class, because I was going on a liveaboard trip).

But $100 for the Nitrox class is a pretty good deal, especially if it includes the books/tables. I really enjoyed the class and it really teaches you a lot about the dive tables that you didn't learn (or remember) from the open-water class.

Is it something you need for the type diving you do? no, but it might be usefull in the future. I think it's a great class to take.

 

[Rick Murchison]

Assuming you have a SCR of 0.6CFM (not bad for the "normal" recreational diver), an AL 80 will last you about 30 minutes on a 60' dive and get you back to the boat with 500 psi.
So, if you want to do a series of 60 foot, 30 minute dives over the course of a day, let's take a look at required surface intervals using air and using NOAA Nitrox I (EAN32). I'll use the Navy tables with doppler limits for this example, but other tables will yield similar results.
After dive one, Air - RG is "F"; Nitrox is "E"
In order to make the second dive on air, you must reduce your nitrogen load to RG "C"; to make the second dive on Nitrox, your RG must be reduced to... well, "E" is ok, so it doesn't need to be reduced at all.
Therefore, the minimum surface interval required for air is 2 hours 29 minutes, and the minimum required for Nitrox is 10 minutes - but we'll go ahead and use the recommended whole hour, and start dive 2 as RG "D" for Nitrox.
Dive 2
Air - Start RG is "C"; end RG is "H"
Nitrox - Start RG is "D"; end RG is "H"
Now, in order to make dive 3 (60 ft, 30 minutes) I have to get back to RG "C" for air, and RG "E" for Nitrox, so my required SI for air is now 3:21, and for Nitrox it is 1:42...
and so on.
So, to make three dives to 60 ft for 30 minutes each, I've needed to spend nearly six hours in surface intervals for air, or two hours 42 minutes (less than half the air SI) using Nitrox.
Whether that "makes any sense" or not depends on how you value your time...
S

 

[pharmguy]

So, to make three dives to 60 ft for 30 minutes each, I've needed to spend nearly six hours in surface intervals for air, or two hours 42 minutes (less than half the air SI) using Nitrox.
Whether that "makes any sense" or not depends on how you value your time...
S

Excellent illustration.

I put off my tropical diving vacation until I get Nitrox certified so that I can max out my bottom time.

$100 to cert and $100 for the fills to get an extra 1-3 dives in per day seems like a good value to me. Especially if you are spending big bucks to get there and have a limited time frame. If you only want 1-2 dives per day it may not be needed.

 

[yknot]

Quick qestion for you all, sorry if this is in the wrong forum:

Does it make any sense to dive with Nitrox for shallow dives? If 90% of my dives are to 60 feet and less, do I really need Nitrox? So far I am OW and perfectly fine using air, but I am curious. Is that mostly for deeper dives? I've been told, it's only 100 dollars to get certified, but If I don't really need it, that's 100 dollars I could have spent on something else, right? (like my cell phone bill )

Nitrox isn't really for deeper dives, at least not for what recreational divers consider deep. The reasons for using or not using go beyond this thread but basically, you would use a nitrox blend in order to limit the amount of nitrogen you are breathing. The flip side is that the replacement gas for the nitrogen is oxygen, which becomes toxic when used in too great of an amount and/or at too great of a depth. For the price of the class, if you think you will take a trip in the future, especially a live aboard, it could be well worth it. Personally, for a couple of dive a day, I wouldn't spend the money required to dive nitrox but at least with the cert you can make that call yourself.

 

[StSomewhere]

If you own the tanks and at some point you put standard Grade E air into them, the tanks and valves would have to be oxygen cleaned before your dive shop would put nitrox in them again via partial pressure blending. Depending on any number of factors (cost, availability, how often you use nitrox, if your diveshop does fills from banked nitrox) it might be easier to use a standard nitrox mix in the tanks all the time. If you rent tanks, the diveshop will have separate rental tanks for nitrox and Grade E air.

 

[aquaoren]

IMO, Yes.
I feel better and less fatigued after couple of dives with Nitrox as if I would have done them on air. Not taking into account the increased safety margins........

 

[The Kraken]

"Does it make any sense to dive with Nitrox for shallow dives?"


. . . to whom???
If it makes sense to you, then by all means do so. It won't have any negative effects other than additional cost.

 

[RonFrank]

Others have provided some numbers to show that YES, Nitrox can extend bottom times, reduce surface intervals, and allow for more diving even with shallower dives. Nitrox in a larger tank certainly is applealing.

However Cell phone bill vs. Nitrox? What RU thinking? Get off the dern Phone!!