2nd Deco Bottle

Hi all,

Tomorrow I'm getting a second deco bottle, an aluminum 40 cf like my current one. I have 2 questions regarding this as I have never carried 2 before.

First, when carrying two 40s on the left side (Halcyon BP/wings setup) do most folks simply hook the individual clips to your D-rings or do you hook the individual clips to a larger clip which then hooks to the D-ring? This method is shown at http://www.dive-rite.com/resource/stage/10.htm about the middle of the page. The site is basically a Dive-Rite ad but that particular idea looks pretty good to me. Anyone using it?

Secondly, my current deco bottle is dedicated to 100%. Conventional wisdom would say I should dedicate my second one to 50%. EANx 50 can be a little tough to get sometimes. I was thinking of dedicating it to standard NN-II 36% which can always be had.

I ran tables on various dives in my usual range and this gets me out of the water approx 2 minutes after 50% would and still gives me plenty gas to do all my bad time on my stages. Anyone see any reasons this is not a good idea?

Thanks much,

Tom

Most of your deco stops for a 150 -230 ft dive will start in the 70-100ft range so in order to make better use of the high PO2 at 70' I would use the 50 vs the 36 even though you could get on the 36 @ 100'. The 50 will increase the gradient, allowing better inert gas offgassing. It only takes 1100 psi of O2 and an air top to 3000 for 50% seems if you can get 100% to 3000 psi 50% should be as easy.
I carry both bottles on the left and clip each one separately to my Dring more than 2 bottles will require a set up similiar to which you are referring.
Just my $.02....Friggincold

Originally posted by Friggincold
if you can get 100% to 3000 psi 50% should be as easy.

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Normally true obviously. My thinking was that there may be times when I can't get anything beyond 36 at any pressure.

Tom

I'm still in favor of the 50% over 36%.Give me an example where you couldn't get anything but 36% .You may wish to check the NAUI RGBM tables as I believe they use 36 eanx...but they usually require an 80 Cuft tank to carry enough gas to do the deco.
Friggincold

I second the use of 50% and for some dives the use of two 40s as you have set up ~32-36 ish and 100% will give you a very slim deco advantage in the 20-25 min dive range at ~200+ (about 2 mins...really nothing over using 1 bottle of 50%). An example for S FL would be the Lowerance. Run some tables and see. You might have to 'get creative' with your local fill station. So if you are married to the idea of a two deco gas dive for this stuff then run 50 in the place of 36 and gain a slight advantage plus be in a better position to go to contingency tables if you lose either bottle (ie you don't have to hang forever...even if the gas would last and your buddy didn't help you out).

Clip direct to Dring do this for both 40s and/or 80s. No extentions.

Originally posted by Friggincold
I'm still in favor of the 50% over 36%.Give me an example where you couldn't get anything but 36% .You may wish to check the NAUI RGBM tables as I believe they use 36 eanx...but they usually require an 80 Cuft tank to carry enough gas to do the deco.
Friggincold

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Originally posted by maddiver
So if you are married to the idea of a two deco gas dive for this stuff then run 50 in the place of 36 and gain a slight advantage

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You guys are convincing me. It seemed like a good idea when I had it :upset:

As for using 2 bottles, no, not married to that but definately engaged to the idea of not slinging an 80. 2 40s will be much easier for me to deal with and just trying to get the most benefit out of what I have (and can get cheaply).

Your advice is greatly appreciated.

Tom

I concur with 50 instead of 36 for dives in the specified depths. I was a big fan of 36 and 80, but through the assistance of LY and others, I have changed my ways.
We clip our bottles differently, though.
I use suicide clips on both ends of my 100%, a suicide clip on the neck of the 50%, and regular clips everywhere else, including bottom and travel. This won't work if you are carrying the 100% and 50% with you the whole time, but is great if you can drop them.
Reasoning being that if you can't see, you can feel by clips which is which, for what it's worth.

Ok I don't do the type of diving that you guys are talking about but I've read alot about it and almost always suicide clips are referenced as a definate no no!

Just wondering if what I'm reading is out of date or not in touch with the real world?

Regards - Dave.

Suicide clips are still out.

They still remain a good line snagger on anything you would use them for on your rig (stage bottle rigging, pressure gauge clip, backup light attachment, etc.) Also these are the single cheapest item in many respects to replace. If cost is an object (albeit it isn't that much, you could go with brass snaps....although eventually you will end up buying the good quality SS ones). This goes for cave, wreck, and ow environments

Originally posted by dlarbale
Ok I don't do the type of diving that you guys are talking about but I've read alot about it and almost always suicide clips are referenced as a definate no no!

Just wondering if what I'm reading is out of date or not in touch with the real world?

Regards - Dave.

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I wouldn't carry 36% as a deco mix its a waste of time(but is a choice for a travel bottle albeit usually using an 80cf).. If carrying 2 bottles I sling 1 on each side.. If I don't need a travel mix(and decide to carry 2 bottles) I'll carry 50% on left, 100% on right or just 50% for many profiles the advange of 02 is that much over 50% and I can go on 50% at 70fsw and keep my o2 clock much lower. If I'm not using trimix I rarely use 100% if I'm on mix I'll switch to 100% unless something prevents me from doing so.

If I need a travel gas, I'll use either 32% or 36% slung on the left, 50% on the right and I'll leave o2 hanging on the line.. I'll build my tables to deco on 50% and a second set switching to o2 at 20 ft.


When I'm using my CCR I always carry 2 bottles(for planned deco dives), 1 with bottom gas Air or a trimix acceptable for the planned depth, and 50% for deco and as a source for an enriched gas mixture for the loop(in event of 02 failure)... 50% is not optimal for maintaing the loop, but it works adequately. If I have another CCR diver with me we both carry bottom gas, 1 carries o2 the other caries 50%.