stage vs deco bottles? Newb questions

[naedward81]

Ok, I'm a newb here and am trying to learn all that I can. I have read, here and on websites, about stage bottles and deco bottles. What is the difference between the two? Is it the same as a pony? If not, then whats a pony? Thanks in advance for any responses.

 

[Jimmer]

ok, well the way I see a pony, you use it for emergencies only. A stage you use to extend your bottom time, and a deco bottle you use to accelerate your decompression schedule. You can use the same bottle and rigging and regulator for all 3 purposes.

I hope that helps.

JIm

 

[Dive-aholic]

A stage bottle is used to either give you more time underwater or to get you to a certain point in your dive before switching to back gas. Typically I use a stage bottle to give me more time. I will breathe 1/3 of the starting pressure, drop the bottle and continue the dive on my back gas, breathing 1/3 of that. I turn the dive and pick up my stage bottle on the way back out. You can also use a stage bottle with a different mix to get you to a certain point such as in a cave system like Peacock III. Many divers will dive 32% in their stage bottle back to the Hendley's Castle jump, drop the bottle and move to their back gas, which is trimix (Hendley's Castle bottoms out in the 180' depth range).

A deco bottle usually contains anywhere from 50% to 100% oxygen. It's used at certain depths to help you off gas the nitrogen loading from the dive. I can shorten a decompression from 36 minutes to about 15 minutes by switching to 100% oxygen on my typical dive profile.

A pony bottle is used as a back up independent air supply. You only breathe from it in emergencies.

Stage bottles are usually AL80s. Deco bottles are usually AL40s. Pony bottles are usually AL30s. Of course, you will find different sizes and bottles on different divers, but those are the most common ones.

 

[naedward81]

thanks guys, that helps clear the air a little. now, in some pictures I have seen, are the stage/deco bottles the ones they have slung at there side? And as Jimmer said, how do you use the same bottle,reg, and rigging for that?

 

[limeyx]

thanks guys, that helps clear the air a little. now, in some pictures I have seen, are the stage/deco bottles the ones they have slung at there side? And as Jimmer said, how do you use the same bottle,reg, and rigging for that?

Stages are usually slung on the side (either all on one side or some on each side) but can also be clipped behind a diver on a leash (a length of rope that lets the tanks sit behind and out of the way)

Sometimes we get sloppy and lump stages & deco bottles into the term "stages" -- this can be confusing.

Also, stages can be used differently in open water as compared to in a cave.
For Open water, usually we dont need to dive 1/3's as in a cave, so it makes sense to breath the stage dry first, and then switch to the doubles.

This is beneficial because you generally cannot easily share a stage with an OOA diver (only 1 reg and it would be messy with 2) and if you have to ditch as stage bottle (in an emergency), better to ditch an empty one also.

stage bottles in open water can also be called "bottom stages" (the inference being they are used at the deepest part of the dive as compared to a deco bottle which will generally be used on the ascent)

This term is probably not used in caves so much as they can have signficant variations in depth and the "bottom" can be hard to define

A stage bottle generally has an MOD (max operating depth) below which you cannot use it. This depth is usually indicated on the neck of the cylinder (in meters or feet) in big numbers

 

[limeyx]

And as Jimmer said, how do you use the same bottle,reg, and rigging for that?

The rigging is just two boltsnaps (with loops big enough to get a finger in), some cave line, fuel hose and some circular metal "bands"


Here is a good guide to rigging a stage
DIR-diver.com - Reg config stages/deco

the same way can be used for both as the clips just go on to the D-rings (for me on the left of my harness at the shoulder & the hip) and the distances are standard.

The MOD on each bottle indicates when it is safe to breathe (along with a safe procedure for switching team members onto and off of each bottle)

Obviously stages & deco bottles are things that should be left alone w/out proper training and mentorship .. but you knew that

 

[Meng_Tze]

Nice clean answers, thanks for that.