AL 80 as a pony

[Nasser]

Have used a pair frequently as deco bottles. I prefer slightly smaller cylinders for this but it's not that noticeable once you're in the water. As has been mentioned, you should take their buoyancy characteristics into account as they can get a little floaty as they empty.

 

[mick allein III]

Thanks most helpful. Tbone. Explain sidemount and bungee bottle. Have a picture?

 

[Nasser]

Thanks most helpful. Tbone. Explain sidemount and bungee bottle. Have a picture?

Check out the article Stage Bottles in Tech Diving Mag issue #11

The eleventh issue of Tech Diving Mag is available for download at www.techdivingmag.com

Contents:
* Yet Another Benchmark - Part I
* Stage Bottles
* Book Review: Force Z Shipwrecks of the South China Sea
* Continuous Gas Blending Using Double Oxygen Analyzer
* Diving Pioneers & Innovators: A Series of In Depth Interviews (Bob Ballard)

 

[WarrenZ]

Also google oms travel bands or independent doubles allows you to back mount two 80s if your BCD can handle it no problem if you have a bp/w already.

 

[raftingtigger]

I backmount a HP100 and sidemount an AL 80 frequently. 1+ for the posts above. Make sure to ballast for the gas you use. The thing I like about it besides a good source of redundant gas is that I can use more of the fill than diving a single tank. The other day I dove for 100 minutes using both tanks. The next dive I kept the HP100 with 1900 left and sidemounted a fresh AL80. I would have never started a dive with just the 1900 left in the HP100. Used most of that up with enough left in the AL80 for its use the next day.

To keep my redundancy options fully open I swap which tank I'm breathing from every 500 psi. That is not for trim, but to keep some gas in each tank.

Most of my diving is shore based. 2 sidemounts take more effort for me than having one on my back and clipping the other on after getting in the water.

 

[Doc Harry]

I did a lot of solo diving in Hawaii last year, had to rent an AL80 for my "pony."

What a PITA.

 

[Six Feet Under]

I've done it before. It was a last minute rigging of someone else's equipment.

 

[boat sju]

Mick,

Where are you going? It might be easy to rent a 63.

 

[DevonDiver]

I dive with AL80's for deco bottles regularly, it's not a big issue. However, if it looks like you'll be routinely diving a single + AL80 pony, especially if travelling, why not just go for the optimal solution: a sidemount BCD.

You do two dives with two tanks, whilst retaining a redundant reserve across both tanks. Many sidemount BCDs are significantly lighter and less bulky than backmount BCDs. It's far more streamlined and less cumbersome in the water.

 

[p1p]

Just remember that an al80 (Luxfer for example) starts at -1.4 in the water(so fairly neutral), but when at 500psi is now +4.4 pounds. And you need to account for that weight swing going from negative to very positive.