Tiny Doubles and Tech question

[Rich Keller]

I do not think tiny doubles and tech diving really go together. I made a set of doubles out of a pair of 30 cu/ft tanks that are great for certain types of rec dives. If you are looking for a balanced and streamlined setup you can not get any better then that.

 

[thez_yo]

I'm a nice tall 5'4" and in small sidemount doubles - Al40s. I'm Rec and it works great... I know other people who dive sidemount 60-somethings and others that have sidemount 80s. The thing about sidemount is, if you wouldn't be able to handle the weight of the backmount doubles, you have the advantage of having the same amount of gas, but getting to split up the weight. A little more thought logistically about how to get you and the tanks into the water, and out of the water, but it's worth it if you wouldn't otherwise be able to do the dive because you wouldn't be able to carry enough gas if you had to backmount.

 

[eelnoraa]

...
Hence my question about a back tank and slung tank for added gas and redundancy. Then a third tank for deco unless the boat has a hang tank (I understand that some boats will provide this for advanced dives). Again, this is all "thinking out loud" at this point.

One tank back gas and sling one stage + one deco doesn't make sense to me. If you need two tanks + deco, just go straight to double.

I think you should also consider how you trim out with the doubles. It sounds like a good idea to have small short double. But in practice, most people are head heavy in double, you have very limited option to add weight to balance it with very short tank. I will suggest look into Faber LP85. They are relatively light weight for double, neutral when empty, longer than HP100, which can help trim. Old LP72 is also easy to handle and trim out if they give you enough gas.

 

[TSandM]

Worthington 85s are not nearly as head-heavy, and don't get butt-light when they're empty, either. I've dived both, and I wouldn't buy Fabers.

 

[uncfnp]

I really appreciate it when posters update their threads so here is mine...

After a cavern course this past August I have decided to go cave. I start the process next April with sidemount into and apprentice and plans for full cave within a year.

Thanks to everyone for helping me clarify my options.

 

[Michael Guerrero]

When you consider what size tanks for cave diving, remember that you are carrying your buddy's emergency gas as well. This will influence tank choice based on your buddy's consumption rate and the $#!+ hitting the fan multiplier.

We dive LP95s or LP104s mostly pumped to 3600 psi. They are big and heavy. This doesn't include the stages and dropping the deco bottles.

 

[uncfnp]

When you consider what size tanks for cave diving, remember that you are carrying your buddy's emergency gas as well. This will influence tank choice based on your buddy's consumption rate and the $#!+ hitting the fan multiplier.

We dive LP95s or LP104s mostly pumped to 3600 psi. They are big and heavy. This doesn't include the stages and dropping the deco bottles.

You are right. I went into this process with a solo mind set and I choose the route that is probably the least appropriate to solo. I am going to need to do a lot of reconditioning for buddy and gas management.

 

[undrwater]

Thanks for the bump though, 'cause I'm eyeing the double lp50's for sale at DRIS. Goal is pretty much the same; solo techreational.

 

[Michael Guerrero]

I'd use these for a rebreather or shallow dives, but that's about it. They are about 70 cu ft each at 3600. If you buy them, make sure to get the HP burst discs in the manifold.

Also, lots of people solo cave dive. Even here in America.

 

[ajduplessis]

Your shoulder problem might be an issue in reaching for the valves. Not being able to reach your valves is a massive problem diving with twins. The only way is to test dive a set in the pool with an instructor. The other possible option would be sidemount.

I would not recommend a rebreather as they are co$tly and potetially dangarous devices in the hand of mortals. We all make mistakes somwhow and a RB will kill you on that day.