How Should A Deco Tank Float ???

[Erik Il Rosso]

This is what I found on the GUE web site:

QUOTE

If the bottom clip is placed too low or is affixed too tightly, then the bottom of the bottle will be pulled higher, and will form a wedge with the front of the bottle. Cylinders should float horizontally and sit parallel to a prone diver.

UNQUOTE

There is a picture above this text and the deco tank does not look so parallel and this is why I am a little bit confused...

This is me with an S80 rigged with an Halcyon rigging kit (bottom leash already shortened) and filled with Nitrox 50, am I doing it right or not ???

YouTube - gorgonie 11/01/2009

Ciao Erik Il Rosso

 

[rjack321]

Depends on how full they are, what's in them, and the water type.

The lower tail needs to be long enough so that the bottle can find its own place in the water. Generally speaking the tail is a hands width long between the band clamp on the tank and the boltsnap. They generally ride base up unless they are full of nitrox.

 

[RTodd]

Didn't watch the video, but what is an S80. Is that a steel bottle or one of the rare aluminum 80s that is a true 80. Either way, wrong tank. Stages need to be Luxifer Al80s or Al40s. Nothing else will trim out properly. Other aluminum 80s can be a PITA. Steel stages are just a non starter.

 

[Erik Il Rosso]

Mine is a Luxfer Al80s.

Ciao Erik Il Rosso

 

[cfenton]

I remember finding that statement confusing when I first started making stage riggings. As rjack321 mentioned, with an AL80 of Nitrox the bottle is going to start out heavy (sink) then become neutral (horizontal) and end up light (floating).

Here is an article that may help you (I realize that you're not asking about making stage riggings), at the the very least it shows you roughly where the bolt snaps should sit:
DIR-diver.com - Stagebottle rigging

You can make the bottom bolt snap shorter by wrapping it under the handle, which may help you get that bottle up from below you.

 

[Erik Il Rosso]

I remember finding that statement confusing when I first started making stage riggings. As rjack321 mentioned, with an AL80 of Nitrox the bottle is going to start out heavy (sink) then become neutral (horizontal) and end up light (floating).

Here is an article that may help you (I realize that you're not asking about making stage riggings), at the the very least it shows you roughly where the bolt snaps should sit:
DIR-diver.com - Stagebottle rigging

You can make the bottom bolt snap shorter by wrapping it under the handle, which may help you get that bottle up from below you.

If you re-read my fisrt post you will see that I use a Halcyon rigging kit designed for AL80 (pretty standard I think) and that I have already wrapped the bottom bolt snap under the handle...

Ciao Erik Il Rosso

 

[RTodd]

Full, the bottle will be slightly nose heavy but not really noticeably. If you are using heavy first stage or a large brass spg it will be too nose heavy. As it gets lighter, it will go bottom up even more. I don't do any kind of wrapping of the bottom clip with just one tank. However, with two, the "bottom" tank gets wrapped so it sits closer and the tank on top will sit on top of it and, when the first stage has been used, help hold it down. They never really truly sit perfectly horizontal. If an empt stage is really getting in the way, you can wrap it or leave it unwrapped and clip it to your scooter ring instead.

 

[DIR-Atlanta]

Didn't watch the video, but what is an S80.

"S80" is a Luxfer designation for their "classic" AL80s, which are the correct tanks for stage bottles, per DIR recommendations. The S80 marking is stamped directly into the neck of the tank, and distinguishes it from the S80N/NB80 (or "neutrally buoyant" 80, which is the wrong tank).

Note that a complete list of specifications for Luxfer SCUBA cylinders can be found on the Luxfer website.

 

[rjack321]

If you re-read my fisrt post you will see that I use a Halcyon rigging kit designed for AL80 (pretty standard I think) and that I have already wrapped the bottom bolt snap under the handle...

Ciao Erik Il Rosso

Just because its made by Halycon doesn't mean much. They make CCR wings afterall...

Why are you wrapping the lower snap? The only time I do that is for cave diving when I don't want the butt of the tank to bang the ceiling. In the ocean I just leave it the standard hands width and the butt of the tank evenutally ends up floating a bit. The extra slack is good for me to get dry glove rings into that space for the spg, etc.

I didn't see anything unusual in the video, looks like a typical al80 full of nitrox in the ocean. Personally for a one deco gas dive I would bring an AL40. Al80s work (and you can get 2 dives off one) but since they are quite a bit larger its more obvious you have it along.

 

[cfenton]

If you re-read my fisrt post you will see that I use a Halcyon rigging kit designed for AL80 (pretty standard I think) and that I have already wrapped the bottom bolt snap under the handle...

Ciao Erik Il Rosso

You're going to have to forgive me, I'm not really sure what your question was.

I'm going to assume by the time you are diving an AL80 of 50% you know where the d-rings are supposed to be. And, if you are confident in the lengths of you're stage rigging, there really aren't any variables left. The only adjustment that is left is wrapping the bottom bolt snap through the handle. But, as others pointed out this is really more of a multiple bottle solution (I did not mean to suggest this was what you should be doing, but rather was pointing out a trick to somebody I assumed, by your question, was new to carrying bottles).

Al80s of nitrox are going to be heavy.