Is nitrox worth it for deeper rec dives?

[Random Dude]

Also good to keep in mind that although the perceived increase in NDL might be insubstantial, Nitrox does actually reduce your risk of DCS no matter what the NDL of your comp says.

This is because NDLs are only mathematical models that does not reflect the specific conditions of your body, and you might actually be closer to DCS than what the computer says.

If you are looking to just have the NDL portion display as large a number as possible, might as well just use an ultra liberal algorithm, perhaps Buhlmann with GF set to 120/120.

If you are looking to reduce risk, and have the money to spare, I would say go Nitrox even if your air-diving buddy is limiting your NDL, since decompression sickness is not an exact science, and algorithms still have way long to go before it can "guarantee" anything.

Just my 2 cents on this issue.

 

[scubadada]

You are showing 8 minutes at 130 on air?

I get 11 minutes with DSAT, 1st dive

 

[BRT]

I get 11 minutes with DSAT, 1st dive

On air? What about on 28%

 

[scubadada]

On air? What about on 28%

Sorry, don't have my computers at home in PA, can't run it. Get 14 minutes with 32%, pO2 of nearly 1.6.

 

[2airishuman]

I've going to have some deeper dives (110-130ft) this coming season. I'm wondering if nitrox is worth the cost for the wee bit of extra bottom time! I ran the numbers on my Perdix (medium conservatism). At 130ft with 28%, you only get 3 more minutes of NDL time than on air.

At my shop, I'd pay $14/tank (up to 100cft tank) for custom mix (you can get banked 32% for $12/tank). In addition, I'd have to have a pair of tanks O2 cleaned ($50/tank, so $100).

Hi Marie.

As others have noted upthread, it is generally not necessary to use O2 cleaned cylinders for Nitrox. Most places that offer Nitrox fills will have 36% and 32% banked, and can create other blends by mixing air with the already-banked 32% or 36%, as appropriate.

There is indeed a point of diminishing returns with deeper dives where 32% cannot be used, such as the 110-130 foot dives you propose. Nitrox is most valuable in the 60-90 foot range where 36% can be used. The increase in bottom time, especially with repetitive dives, is considerable.

You will have to decide for yourself why you are making dives that are limited to around 10 minutes of bottom time, what the objectives of the dives are, and whether the extra 3 minutes or whatever contributes to those objectives or your enjoyment of the dive enough to be worth the $20.

 

[hammet]

On air? What about on 28%

13 min (ead of 115 rounded up to 120 on padi table (16 mins if you round down)

 

[NAM001]

I have 2 views on it i dive nitrox when ever possible. i set my puter for the mix. now in shallow water i may dive the puter in the same gas as the buddy is using so long as it is closer to air than i am diving. for deeper dives my puter reflects the gas i am using. if you dive 32% and your puter is set fo rair how do you have any idea where you stand for that last dive of the day that would take you over your exposure limits whether they are ndl or not. the safest thing ti to set you puter to what you are diving if your buddy is on air then he will call the dive and it is no loss to you. You have less RNT than your buddy after the SI.

 

[Barnaby'sDad]

Hi Marie.

As others have noted upthread, it is generally not necessary to use O2 cleaned cylinders for Nitrox. Most places that offer Nitrox fills will have 36% and 32% banked, and can create other blends by mixing air with the already-banked 32% or 36%, as appropriate.

It depends on the area. I’m not aware of any shops in a 1+ hr radius of me that bank Nitrox.

I received some misinformation that one shop in the area does, but when I called the shop in question...the owner confirmed that they do not bank Nitrox.

It sounds like Marie is in a similar position in her home diving area.

 

[ChuckP]

Also good to keep in mind that although the perceived increase in NDL might be insubstantial, Nitrox does actually reduce your risk of DCS no matter what the NDL of your comp says.

This is because NDLs are only mathematical models that does not reflect the specific conditions of your body, and you might actually be closer to DCS than what the computer says.

If you are looking to just have the NDL portion display as large a number as possible, might as well just use an ultra liberal algorithm, perhaps Buhlmann with GF set to 120/120.

If you are looking to reduce risk, and have the money to spare, I would say go Nitrox even if your air-diving buddy is limiting your NDL, since decompression sickness is not an exact science, and algorithms still have way long to go before it can "guarantee" anything.

Just my 2 cents on this issue.

This but I'll just add:

Check where you would be filling tanks - technically O2 clean is only needed when using mixes above 40%. One should be able to mix 28% in a non O2 clean tank if they bank something greater than 28% - Banking is pretty common but it's the shops choice I suppose.

An O2 clean item exposed to normal compressed air is no longer O2 clean and would need cleaned again. Look at deco regulators and bottles - they are all labeled special in some way. Nitrox tanks do need labeled though - or are supposed to be at least.

You've dove enough at these depths to know how you feel after diving, fatigue is a symptom. Try good blends of nitrox some time and see if you feel better. You'll need the nitrox class before AN, even if you don't use it, knowledge is helpful.

Diving air makes me tired period. I feel way better breathing an enriched mixture and could care less what others around me are breathing. A one off dive, maybe even second dive you don't notice as much - but 3rd, 4th or multiple days - I really feel the difference.

The bottom line is safety, the less N2 in your body the safer you'll be.

Then you'll do your AN/Deco class and dive air to 150' - HaHa

 

[johndiver999]

Why not find buddies who dive nitrox?

Seems crazy to sacrife 40 % of you dive time because you picked the wrong one. I would dive 32% in that depth, and have a lot more time. When you get to 160’ then air
Makes sense to me.