Deco mounting position

[seedy]

I am about to carry a small deco bottle. 2.7l. On my next sidemount dive. I am a bit confused as to the process and mounting options. Should it be mounted on top or underneath the primary bottle . can you reach behind and access it or would you have to bring it around to use it. Similarly with larger stage bottles side mounted on top of the primary tanks , do you use those in position or do you have to swap position with the primary tank. Plenty of rigging info out there but no operational info Thanks for any advice. It is priceless

 

[JohnN]

I am about to carry a small deco bottle. 2.7l. On my next sidemount dive. I am a bit confused as to the process and mounting options. Should it be mounted on top or underneath the primary bottle . can you reach behind and access it or would you have to bring it around to use it. Similarly with larger stage bottles side mounted on top of the primary tanks , do you use those in position or do you have to swap position with the primary tank. Plenty of rigging info out there but no operational info Thanks for any advice. It is priceless

That would be a 19 ft^3 over here where we still practice furlongs and fortnights. . . . Way to small for a deco bottle. Did you intend to ask about this as a pony? Either way the rigging is the same, here is a good place to start: Rigging Stage Bottles? How to carry extra scuba tanks? and why. | SDI | TDI | ERDI


----Check that -----

I just realized you're diving sidemount and don't need a pony bottle. Forgetaboutit that bottle is too small.

 

[Dive-aholic]

Decompression cylinders should be mounted below. There are people who dive sidemount that mount on top and insist that's the only way to do it but you cannot properly verify and confirm the gas you're about to breathe if it's behind you. Some say they can, and they probably do, but most of us just aren't that flexible. I'm not usually black or white about how to do things but this is a safety issue. You must be able to verify and confirm and follow that hose back to the 1st stage regulator before breathing off of it.

 

[Scott]

I have carried deco bottles on the top and underneath. There is no right or wrong location, you need to try both and decide which location works best for you.
JohnN shared a link for staging that works. I used that method when carrying deco cylinders underneath. I currently carry mine on top of the mains using a tip from Rob Neto (Dive-aholic) here on SB
Sidemount Stage Rigging « Rob Neto

 

[JohnN]

Decompression cylinders should be mounted below. There are people who dive sidemount that mount on top and insist that's the only way to do it but you cannot properly verify and confirm the gas you're about to breathe if it's behind you. Some say they can, and they probably do, but most of us just aren't that flexible. I'm not usually black or white about how to do things but this is a safety issue. You must be able to verify and confirm and follow that hose back to the 1st stage regulator before breathing off of it.

I was taught to use a pocket on the deco bottle. SCUBA Diving Equipment for Technical, Sidemount, Rebreather, Wreck and Cave Diving: Dive Rite, Inc - Product Catalog - O2 Second Stage Pocket

 

[DevonDiver]

I've experimented considerably with optimal locations for deco bottles for sidemount. I have to agree with Rob Neto, under-slinging provides the greatest accessibility/visual coverage of the bottle/s - and that's a safety issue, so it trumps convenience.

Stages (extra bottom gas) above and deco below...

 

[seedy]

Thanks for all your insight . Much appreciated.

 

[Dive-aholic]

I was taught to use a pocket on the deco bottle. SCUBA Diving Equipment for Technical, Sidemount, Rebreather, Wreck and Cave Diving: Dive Rite, Inc - Product Catalog - O2 Second Stage Pocket

That's not enough confirmation. The 2nd stage regulator needs to be followed to the 1st stage regulator and the bottle it's attached to verified and confirmed. It is not enough to simply look at a 2nd stage or a pocket and assume it was attached to the correct bottle.

 

[kwinter]

I currently carry mine on top of the mains using a tip from Rob Neto (Dive-aholic) here on SB
Sidemount Stage Rigging « Rob Neto

That's kinda funny considering Rob's post directly above yours.

Decompression cylinders should be mounted below.

I don't mean to imply that Rob is schizo or anything.........

 

[DevonDiver]

That's kinda funny considering Rob's post directly above yours.

I don't mean to imply that Rob is schizo or anything.........

Knowing the difference between a stage cylinder and a deco cylinder would ease your obvious confusion.

Rob is absolutely consistent in his advice.