Is nitrox worth it for deeper rec dives?

[Marie13]

@Marie13 In your situation, why not just get banked nitrox. Banked nitrox does not need to go into oxygen cleaned tanks since you are not dealing with high % of oxygen. I hope and seeing that in the near future, more and more shops are offering banked nitrox. Recently I saw one offering 32, 34 and 36% banked nitrox, no cleaning required.

DRIS is the only shop I know of locally that banks. It also doesn't seem to be readily available when traveling. Remember - I'm diving the Great Lakes, not in Florida. And when I travel, I don't want to have to haul more than 2 tanks with me. The people I carpool with would not appreciate it, especially if they rent tanks at destination.

Also, I'm not going to limit myself to wrecks at 111ft or shallower.

 

[Doby45]

Nevermind...

 

[Centrals]

If I can do multi-level dive than I won't bother with nitrox.
If it is a square profile eg. wreck with max depth at 30m then nitrox is a winner.

But I will always use the same mix as my buddy no matter what.

 

[Marie13]

Perhaps I might missing something, but why do your tanks need to be O2-clean? They should be able to give you a 32% fill from the bank even with lesser cleaning standard, and then just top it off with air to get to 28%. No partial pressure blending with pure O2 needed.

Nope, you want custom blends, you need O2 clean tanks. And O2 cleaned tanks are necessary for any of my trips. I've yet to find banked nitrox at any of my possible destinations.

 

[Doby45]

Why even open a thread when you already have your mind firmly made up? Makes zero sense to me.

 

[Zef]

It depends on what there is to see down there. If you are carrying a camera and find an amazing shot then those 3 extra minutes can be the "chance of a lifetime", but if you are just meandering about around the outside of a wreck then those 3 extra minutes may equate to less value. Only you can decide how much the limited increase in bottom time means to you. If you were to dive nitrox to increase conservativeness as a means to reduce the chance of DCS then every measure you take can be considered of potential value, but that is not the case when using Nitrox to increase bottom time.

-Z

 

[scubadada]

Marie, you've painted yourself into a corner, enjoy it there

 

[Marie13]

Marie, you've painted yourself into a corner, enjoy it there

We pretty much all know I'm a stubborn b**ch. Excuuuuse me for thinking out loud. I'll try to remember next time that such threads are not tolerated here.

 

[BRT]

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).

Most of my diving is only 2 dives a day. Occasionally I'll do 2 Lake Michigan charters in 1 day (4 dives), but most of those are shallower (less than 90ft, most under 70ft). I have a trip to the Straits of Mackinac in June (3 days of 2 dives each) and Toby in July (1 day of 4 dives 1 day of 2 dives). I'll be taking my own tanks on the Straits trip, and am up in the air about the Toby trip (Divers Den only has 6 HP100 tanks for rent) - I refuse to dive aluminums now. Screws with my weighting.

I got a pair of tanks O2 cleaned last summer, but I really only used the O2 cleaning when I was on my Alpena, MI trip. I could have easily done those dives on air.

I've debated this with several friends and they all just do deeper rec dives on air. I didn't get my new doubles setup (tanks I already had) O2 cleaned, either.

What is 3 minutes at 130? 50-60% more bottom time?

 

[claymore]

An interesting thought is that O2 clean is only as good as the last fill. If the fill is not Oxygen Compatible air the tank is not O2 Clean. If the tank has been filled somewhere that the partial pressure blender isn’t familiar with and trusts the air they use can, with good reason, refuse to partial pressure fill with O2.