Considering small doubles (~50's)

[GrumpyOldGuy]

How deep do you dive? Double 50's sounds like a ridiculous solution to me... If you want to reduce gear, use the 100 steel and drop the pony down to even a 6 cu-ft tank.. That should get you from 100 to zero feet, with very little trouble and negligible weight and drag (and cheap too).

I did the LP 50's thing 30 years ago for commercial charter boat dives. They were fun to dive and I had free fills. But the overhead of dealing with doubles was not worthwhile on shore dives. Just a simple run of 2 shore dives required a run to the dive shop and loosing my parking spot. They were heavy hiking up the stairs after the dive and were high maintenance.

The wide spread availability of HP steel tanks now days makes for a cheaper, lighter, simpler system and swapping tanks is fast.

 

[Paladin]

I have a set of baby doubles: Catalina AL53s.



I also have a set of steel 72s. On both I use traditional center post manifolds (one regulator in the middle). This setup gives me doubles with the simplicity of singles.

 

[Rich Keller]

The small set of doubles will distribute the weight across your back and bring that weight closer to your center of gravity. I am not familiar with the freedom plate but the first thing I would look at is connecting the tanks directly to the plate so the plate also acts as your tank bands. This will get the tanks as close to your center of gravity as possible. You may even be able to modify the plate yourself without the need for a machinist. I did something similar with a couple of 30 cu/ft tanks I had left over from another system attached to a Dive Rite aluminum plate. This also works well for shore dives that require a long surface swim and surf entry dives.

 

[HowardE]

We have 3 sets of these double LP steel 50's in our dive locker and another 2 sets of double LP 45's. They are OMS tanks made by Faber.



Here are the strong points in my opinion.

1) We pay for fills by the cubic foot, so there's no additional fill cost.
2) They have plenty of gas for any of us on any recreational or shallow wreck dive (< 150 feet)
3) They trim out great in the water
4) My wife loves them. They're her favorite tanks to dive with.
5) They're so small and relatively light weight (not much heavier than a single steel 120) that my wife dives them with a #32 singles wing (the Apeks WTX3)
6) They are double tanks, so they have redundancy with respect to regulators. The only caveat is that there is no isolator.

 

[Rich Keller]

There is someone trying to sell a set of double 46s here.

http://www.scubaboard.com/forums/cl...82-faber-oms-twin-manifolded-46-lp-tanks.html

 

[Mustard Dave]

I haven't dove doubles, but it seems to me that this configuration will not give you as much gas as the your single 100. If you dive the twins and set 500 psi as your flat minimum (forgetting about reserve for the moment) you are going to leaving a lot more gas in the bottles. Also, my steel 100 weighs something like 45 lbs. ( I have the exact number some where) and if you are going to put twin AL 50 on, you are going to be adding additional ballast. Nothing prevents you from doing this, but it seems like the benefits are small when you think about doing a shore entry with 66 lbs of tanks on your back. For the weight, I would think a 100 or 120 would be a better investment. The cost of maintaining a single larger tank will be much lees than a pair of twins. If you are interested in more more gas from a safety perspective, maybe an upgrade on the pony might be good, or as was suggested, going side mount. Seems like they might be more practical for shore diving solo. Side mount will lower your center of gravity in surf and would give you better trim and more access to the manifolds.

If you are diving independent twins, your pint about the available gas would be correct. A manifolded twinset is no different in terms of available gas as a single cylinder with equal capacity.

I have a set of baby doubles: Catalina AL53s.

View attachment 146989

I also have a set of steel 72s. On both I use traditional center post manifolds (one regulator in the middle). This setup gives me doubles with the simplicity of singles.

I take it you only have one first stage? If so you will have none of the redundancy benefits. With a manifolded twinset with two outlets, you can shut down the offending first stage and still breathe off the other.

My advice to the OP is do it. Ads a solo diver, a redundant gas source is essential and this is a great way to do it without carrying more weight.

 

[Paladin]

If you are diving independent twins, your pint about the available gas would be correct. A manifolded twinset is no different in terms of available gas as a single cylinder with equal capacity.



I take it you only have one first stage? If so you will have none of the redundancy benefits. With a manifolded twinset with two outlets, you can shut down the offending first stage and still >breathe< off the other.

My advice to the OP is do it. Ads a solo diver, a redundant gas source is essential and this is a great way to do it without carrying more weight.

For my purposes, redundancy is not a factor. I want to dive doubles from time to time but I do not want the, for me, unnecessary complexity of an isolation manifold and two first stages. The simplicity of a single regulator on a traditional style twinset is exactly what I want and need.

 

[Mustard Dave]

I have a set of baby doubles: Catalina AL53s.

View attachment 146989

I also have a set of steel 72s. On both I use traditional center post manifolds (one regulator in the middle). This setup gives me doubles with the simplicity of singles.

For my purposes, redundancy is not a factor. I want to dive doubles from time to time but I do not want the, for me, unnecessary complexity of an isolation manifold and two first stages. The simplicity of a single regulator on a traditional style twinset is exactly what I want and need.

The OP is solo diving, so in his case, redundancy is vital.

 

[Paladin]

The OP is solo diving, so in his case, redundancy is vital.

I also dive solo on occasion. Until a couple of years ago, ninety percent of my diving was solo.

 

[Hatul]

How deep do you dive? Double 50's sounds like a ridiculous solution to me... If you want to reduce gear, use the 100 steel and drop the pony down to even a 6 cu-ft tank.. That should get you from 100 to zero feet, with very little trouble and negligible weight and drag (and cheap too).

I don't think a 6 cu ft tank is enough to ascend safely from 100 ft.