Question about Nitrox and computer

[Tatakai]

I am about to take my Nitrox class and dives the weekend and wanted to ask about the computers that are out there. I have a computer that isn't Nitrox rated and wanted to see if I could still use it until I get the nitrox computer down the road when funds are more available. I would use the charts to plan the dive and have the computer to measure pressure in tank. Looking for advise and info on the rout to go until I can get the nitrox computer.

Thanks

Tatakai

 

[Diver Dennis]

Yes, as long as it's only for pressure or depth it would be fine or you could just use an SPG. Very important to know the MOD for the mix you are diving.

 

[drglnc]

know your mod and use your slates to plan and calculate the dive. Use the computer as gauges only. If it has a gauge mode turn it on so it doesnt give you false remaining bottom times and nitrogen loads. did i mention know your mods. Plan he dive and DIVE YOUR PLAN. be safe.

 

[victor]

know your mod and use your slates to plan and calculate the dive. Use the computer as gauges only. If it has a gauge mode turn it on so it doesnt give you false remaining bottom times and nitrogen loads. did i mention know your mods. Plan he dive and DIVE YOUR PLAN. be safe.

Surely diving the remaining bottom time and nitrogen loads is safe. Having the computer on air and diving nitrox, these numbers will be much more conservitive.

You will just have none of the advantages of diving nitrox.

 

[The Chairman]

Diving NitrOx as if it were air is the ONLY way to increase safety. Just be sure to MARK your computer with your MOD so you don't forget. Use tape and a sharpie. Far from losing ALL of the benefits of NitrOx, you will create a HUGE benefit.

However, diving tables and a computer? Just put your computer into gauge mode. You will lose the benefit of multi-level diving that the computer handles so well.

 

[J75]

As stated above, use your computer as a depth and time guage, just be sure to watch your depth limits per your tables. Your computer could freak out though if it thinks you're going into deco, and may not work for subsequent dives if it has a mandatory SIT after decompression violations. You could always just dive the Nitrox as you would 21%. Just be careful of your depth.

 

[DeputyDan]

Use your Nitrox dive tables - not your air tables.

Everyone is right about the MOD.

 

[divingjd]

If you use a non-nitrox computer while diving nitrox, two things happen: (1) you don't get the benefit of extended bottom time that you can get with nitrox; and (2) you don't track your O2 exposure, which is an issue for oxygen toxicity, primarily pulmonary oxygen toxicity. Lots of people (I am one of them) often dive nitrox with the computer set to air, or with air tables. This means that you get an extra margin of safety, because your actual nitrogen load is less than the tables or your computer is assuming (taking into account the theoretical nature of the nitrogen loading assumptions). So you can use your non-nitrox computer to dive nitrox. You will just be trading one benefit of nitrox (extended bottom time) for another benefit of nitrox (extra margin of safety). But what about the O2 exposure? As long as you are diving a typical recreational dive schedule of two or maybe three dives a day, you are not going to have an issue. You have to do some pretty intense diving to get into an O2 clock issue.

So go ahead and use your regular computer, just watch the MOD (as others have noted - CNS O2 toxicity is nothing to take lightly) and don't try to wing it on extending your bottom times. If you are doing multi-level diving, I would guess (and it is only a guess) that you will not benefit (in terms of bottom time) from using nitrox tables over an air computer, because the tables still assume a square profile. It is not necessary to put your computer in gauge mode or ignore any bottom time remaining calculation.