Double AL40's?

[Fishyhead]

I dive a set of LP46's which I love. I recently started diving a boat that does not fill the tanks during the first SI. Divers need to bring two tanks for a three dive day. The captain fills the tanks while divers are on their second dive. Since I don't have two sets of doubles, I have to switch over to my single tank setup.

I have an AL40 that I used as slung pony. I was thinking of pairing that tank up with another AL40 to make up a second set of tiny doubles. I'd dive with the LP46's first, swap to the AL40's on the second, and dive the last with the LP46's.

I can't think of any downsides to diving steel and aluminum doubles on the same trip except I'd need to swap in/out some lead to compensate for the buoyancy differences.

Expense aside, can you guys think of any reason why this wouldn't work?

I'm 5'8, 165, dive in a 7mm wetsuit. With the LP46's, I use 5# of lead.

 

[Basking Ridge Diver]

So - you will get all kinds of answers on this one.

I like doubles - but I dive independent doubles. I use bands without a manifold. In essence I loosen the band and replace a tank on my SI. It slides out and I slide a third full tank back in, tighten it back up and go dive. You do not need to dive "tiny doubles" with a manifold and to be honest - I use this approach with my LP85's and LP72's.
I choose to breath both tanks to keep them somewhat balanced - you can choose anyway you want to dive...

 

[runsongas]

the answer is sidemount

 

[formernuke]

I'm curious as to what others say.

P.S.

I like my steel LP 50's.

 

[sea_ledford]

Get a single set of "real" doubles (ie al 80's at least) do the first two dives on that, then fill for the third dive?

I loved diving a set of sidemounted steel 45's, but at a certain point, bringing one set of big tanks is less cumbersome than two sets of small tanks.

 

[lermontov]

you can do that no problem- are you regulators compatible to swap back and forth

 

[Fishyhead]

I'm curious as to what others say. P.S. I like my steel LP 50's.

I'm interested too but not interested in switching my configuration around (either to independent doubles or side-mount)

Get a single set of "real" doubles (ie al 80's at least) do the first two dives on that, then fill for the third dive?

The boat fills while divers are making their second dives, not during the surface interval so double AL80's won't get me through the third dive without a fill. I could double my 95's but that would require a different BCD and be really heavy even without ballast.

you can do that no problem- are you regulators compatible to swap back and forth

Yes, I have dedicated double-tank (Atomic M1) and single-tank (US Divers Conshelf 22) regulator setups. I'd set up the valves on a second set of doubles the same way as my 46's to keep things simple.