Stage Bottle or Backmount Doubles

[Mikebmw325i]

I am a rec diver here in Hawaii and want more air on my dives. (My air usage is pretty good already)
My goal is to moderately longer dives in shallow shore diving spots.

Currently I do about 1 to 1:20 hr dives for shore diving around 30 to 40 feet. I want to add another bottle to this and do longer dives and see more and do the whole dive site in one dive.

I currently have a backplate and wing setup and thinking about either attaching a stage bottle or doing Backmount doubles. My question is which would be better to start with? I was planing on doing a independent double setup or staging a al80 to my side and going that route. How hard would trimming out be for only one stage bottle? Any guidance?

 

[Nirvana]

I think that if you are planning to add a second, "full size" tank, you should go for back mounted doubles or side mount, depending on personal preferences and the dive conditions.

Just be sure to have in mind that you must fully understand the configuration you are to use, its failure modes and solutions to problems, such as understanding manifolds and being capable of determining the point of failure during a dive and operating the valves on your back.

I can tell you that in my case, before I took any technical diving courses - but already planning on doing it - I had an instructor and technical diver who was a friend mentor me on diving doubles.

 

[DustyC]

I'd go sidemount before a single 80 on my back and a sling bottle.

 

[Remy B.]

No hard it all, If you swim slow you don't notice much with that extra bottle on your side, out of the water is where is the difference, but you clip it off and it is done, but you need to have the right gear for that, the correct D-rings and snatch/clip on's, slinging a bottle is a much more flexible setup IMO

 

[sunnyboy]

I do that from time to time. I will stage either a 40cf or an 80cf aluminum bottle if I have planned an open circuit dive where I want "just a bit more gas".

As I dive a rebreather much of the time, I'm used to carrying a 40 or an 80 as bailout on every rebreather dive, so trimming a staged tank is no problem.

I did switch to sidemout my stage/bailout back in 2010 and love it. The bottle tucks in beside me and under my arm and I really don't notice it at all.

 

[doctormike]

Backmounted doubles is a very stable, comfortable platform with a good bit built in redundancy. Manifolded doubles gives you more gas without worrying about switching regulators or emptying a stage bottle - you will have some degree of redundancy further into the dive. As I'm sure that you know, watch your NDLs, doubles makes it easier to go into deco, but it sounds like you are diving pretty shallow.

 

[luscioman]

Are you currently running a single Alum 80? If yes consider a 117 or 120 single tank to get extra time.

 

[sunnyboy]

I found backmounted doubles are heavy, especially if they are steel tanks of any size. I gave them up in 2007 and could not be happier, especially as I get older.

Sidemount is a whole 'nother thing. Like doubles, you really should give consideration to getting training if you pursue that path. For one thing, sidemount gas management is NOT the same as diving a stage and back gas. The rigging is different as well, hence my recommendation for training if you want to go this route.

I like the stage because it's something I can add to my normal OC configuration only if I need the extra gas. Otherwise it stays at home. I can also tailor the tank size to what I need on that dive. I don't have to carry 80cf if I don't need 80cf in the stage.

 

[DevonDiver]

Backmount doubles or sidemount would offer massive advantages in comfort and stability, compared to a single and stage.

Sidemount has further advantages when travelling to dive. You can use regular tanks from any dive center and there's no issues with bands/manifolds availability. It can also be significantly lighter and less bulky in your luggage, compared to a doubles BP&W.... or even most jacket BCDs.

 

[spectrum]

I'm nearly an exclusively a single tank diver. I do have a dive or 2 where I want a lot of air. For those rare occasions I have slung an AL80 shoulder to hip diagonally and it worked really well. Jumping to doubles or side mount for my infrequent need wouldn't make any sense at all. If you go aluminum, thow a camband with #4 of weight on the tank so it's not floating up to your belly when you breathe it down.

Pete