Doubles setup recommendation

[flymolo]

Idk if other ppl would consider 5cf of gas a negligible amount of gas or not but I guess the argument for me would be "which tanks trim better?"

 

[formernuke]

I did not know that AL80 were not actually 80, you never stop learning.

 

[flymolo]

Also, if you are running up on gas reserves to where 5cf of gas would make a difference between a reasonable plan and an unreasonable plan, using a stage bottle is always an option.

 

[Marie13]

Idk if other ppl would consider 5cf of gas a negligible amount of gas or not but I guess the argument for me would be "which tanks trim better?"

Or what conditions are you diving? Cold with drysuit - steels preferred, less additional lead needed.

 

[flymolo]

yeah that's a good point. At home I dive dry, in cold water. i typically use hp100s or lp85s pumped up. on longer dives i'll carry a stage of bottom gas and a bottle of deco gas. warm water cave diving is done in drysuit with double 80s and a stage bottle. one point of interest tho- i don't vary my undergarments between warm and cold water due to exposure times, but early season up here I'll wear a heated vest.

when diving double al80s with thick-ish(?) undergarments 2x4lb trim weights are i need. but i wear 4th element arctics which I know some ppl wouldn't consider particularly thick undergarments

 

[divezonescuba]

I am about 5’7” and have damaged both shoulders. I have dislocated my right shoulder over 100 times and my left shoulder 10-15 times. This includes dislocating my right shoulder twice immediately before jumping in and relocating it underwater during the dive. If that’s your issue, learn how to relocate it yourself. I have opted not to do surgery and just to live with it.

When you do valve drills, it works better for many people if you elbow is pointed towards your head than away. It is also less likely in at least in my case to dislocate, which has never happened during a valve drill.

Normally, I use an al80 twin set and have to use trim weights to offset being foot heavy. I will be going to LP85s which will enable me to do away with those trim weights.

The only problem is a lot of places like the Caribbean, Bonaire, and Egypt mostly have only AL80s twin sets. Buddy Dive in Bonaire is a big GUE facility and they use AL80 twinsets.

 

[Marie13]

The only problem is a lot of places like the Caribbean, Bonaire, and Egypt mostly have only AL80s twin sets. Buddy Dive in Bonaire is a big GUE facility and they use AL80 twinsets.

Guess it depends on where you dive. It's not a problem I have to deal with. My diving is all local/regional and I drive to dive. I have all my gear including tanks.

 

[flymolo]

Guess it depends on where you dive. It's not a problem I have to deal with. My diving is all local/regional and I drive to dive. I have all my gear including tanks.

Yeah, I am not saying I am pro or against the hp80s. but if you travel somewhere and rent a set of doubles, they'll likely be al80s. a few pounds of tail weight will offset the buoyancy.

 

[Marie13]

Yeah, I am not saying I am pro or against the hp80s. but if you travel somewhere and rent a set of doubles, they'll likely be al80s. a few pounds of tail weight will offset the buoyancy.

As I said, not an issue I have to deal with. But for those who travel and want to rent doubles, that's something they'd have to consider. The length difference between HP80s and AL80s is nearly 6". That's a lot.

 

[halocline]

Hey all.

I'm looking for a little advice here.

I'm a shorter guy (5' 7") with a bad back and bad right shoulder and have really enjoyed sidemount for those reasons (tanks hitting my head or legs, and isolation valve access if too high, carrying lots of weight, etc). However, my friends are jumping into the GUE pool and I'd really like to join them .. so it looks like I'm going to give this whole doubles thing a go and see if I can make it work. The main reason being I am interested in learning to be a better dive team member and expand my skills. Even if it means ditching double after learning in favor of sidemount again, I think it would be valuable.

What doubles setup strikes a good balance between not too long and not too heavy? What size would you recommend? Are there any setup tricks for reducing weight? I feel like every little bit matters for me. My friends all stack double water heaters onto their backs and it hurts just watching.

What are some tricks to dealing with a bad right shoulder and valve access? I'm concerned that especially in a drysuit the reach will be painful.

To the OP, you should know that virtually nobody dives twin HP80 tanks, which have been known affectionately as 'bowling balls with valves'. They are very short tanks and most divers would not trim out well in them twinned. Marie appears to be an exception.

AL80 twins are decent IME, actually I think AL80s are much better to dive with as twins than they are as single tanks. The bands/manifold somewhat offset the inherent buoyancy, although they can get fairly butt-light when they're close to empty.

LP72s are nice light tanks that are ok as doubles; I learned to dive twins with them. I'm also 5'7" and I prefer AL80s doubles. Ironically, LP72s are my absolute favorite single tanks in terms of trim, comfort, and gas-to-weight. They're only 27lbs, and with a slight overfill provide just about as much gas as an AL80. But doubled with a manifold and bands, the 80s work better for me. Depending on where you dive, they are usually the most common choice for rental and they're a good starting point for doubles.

If you have real shoulder/back issues, maybe staying with sidemount is a better option for you.