How do you rig and use your doubles?

[Coztick]

Universal acceptance is overrated.

 

[Lorenzoid]

Okay, so if sidemount is the OP's goal, then GUE is out. But surely there must be some instructor within a reasonable distance--maybe a weekend roadtrip--willing to offer a Sidemount course? My experience is only with the GUE Doubles course, but I have to believe a sidemount course would answer all the OP's questions and more--how to select the right gear, maybe try out a few different options before buying, etc. This is such hands-on stuff, I just don't see the attraction of trying to learn the ropes on the Internet and making purchase decisions based on that. I guess different people have different styles for learning. Some people are experimenters. Me, I'd seek out a sidemount instructor before doing anything else, even if it meant a weekend trip.

 

[WarrenZ]

Sidemount inst always the answer however it is a good solution to some of the problems people face with big heavy doubles or traveling with doubles or pony bottles for solo. I spent a week in Cozumel playing with sidemount tanks and boat diving. It worked great for what I wanted to do however it isnt the end all solution if I was going on a liveaboard where we were doing rec profiles and all using single tanks I would go backmount and bring my pony for solo however if you are doing doubles dives sidemount is much nicer because I never have to pick up more than one rigged tank at a time.

 

[Coztick]

Single tank sidemount and a 2l pony on the right works great for me for Coz.
For me, it's about the comfort and posture.

 

[Dave Bevan]

I agree, except that the OP said the nearest dive shop is 3 hours away. Still, even taking a weekend road trip to take a Doubles course could be worthwhile. Part of the GUE course is to give the diver the knowledge to select a set of doubles that suits his intended type of diving. Setting them up, maintaining them, and of course using them (valve drills, etc.)--all part of the course. Independent instructors affiliated with other agencies might also be willing to put together a customized "everything you always wanted to know about doubles" course.

I flew longer than that to attend my course but again it depends on how much you want the training really. I would suggest that sidemount is great but it takes a lot of jiggery to get it right. Its good if your local instructor can guide you but learning yourself is pretty hard. Not impossible.

There are arguments for either which I won't go into. I will state the reasons why I in the end selected doubles over sidemount.

1 - I have no issues manipulating my valves with the twinset on my back.
2 - I already had a BP/W I was comfortable in.
3 - I want to be able to access all my gas should a failure occur and I have to shutdown one side.
4 - GUE have an established system for me to train in Doubles.

This doesn't mean I won't do sidemount in the future nor does it mean I dislike sidemount. It has its uses and I can see why people do it. For example being able to use rental tanks rather than a dedicated doubles set, easier on the back, visibility of your valves I could go on and on.

Anyhow all I'm going to say is whatever you do save the money and spend it on a decent instructor/course. Then once you know what you are doing move on to buying the gear.

 

[tbone1004]

slight correction on point 3. It is extremely rare that you would ever lose the ability to breathe the gas out of a tank in sidemount. Very few failures would remove your ability to feather the valve to be able to breathe out of that tank. less convenient, yes, but easily done

 

[Dave Bevan]

slight correction on point 3. It is extremely rare that you would ever lose the ability to breathe the gas out of a tank in sidemount. Very few failures would remove your ability to feather the valve to be able to breathe out of that tank. less convenient, yes, but easily done

Likewise a failure in the manifold means I still have to plan for half gas. However I prefer to access all my gas without having to feather the valve. I'm not saying it's right it's just my reasoning.

Like it said the day I'm having to remove my doubles to get where I want to go and I'll be all over sidemount. I'm just not at the level yet.

 

[RyanT]

Very few failures would remove your ability to feather the valve to be able to breathe out of that tank. less convenient, yes, but easily done

For those that may not know what feathering a valve is: It is when you open and close the tank valve for each breath. So if you had a free flowing regulator that you couldn't stop, for example, you close the tank valve between each breath to help save gas.

It wouldn't be hard to have another problem to deal with (e.g. assisting another diver) that would increase task loading and make feathering a valve much more difficult. With that said, I agree that the probability of multiple failures occurring while needing to feather a valve is really low.

 

[Compressor]

I dont have any experience with double tank setups, but am interested in getting into it in the future (read: after many more dives, and much more experience and instruction). I have a friend that is an instructor, but she lives in germany and only visits in the summer months, so sitting down to chat about it with her isnt really an option at the moment...

Ive ran into a few sets of manifolds and bands for sale used in my quest for a set of standard rec gear, and am wondering if any of it would be useful to pick up for later use...

My rough plan at the moment is to round up a small fleet of used al80s to have enough tanks for a full weekend of diving without having to go looking for fills. They seem to be fairly plentiful and cheap in my area (im on a budget), and i dont see many steel tanks around here for sale used. My LDS is a three hour round trip, and if theyre busy i would have to leave them and come back to pick them up. If i have to do that id like to end up with a good supply of air for lots of dives once im done driving around. I havent bought any tanks yet, but am considering a few.

So then with some used doubles stuff floating around, it got me wondering if i could/should eventually double up a couple al80s to give longer bottom times. Would likely be at fairly shallow depths, scallop diving and the like. What should a guy consider for this? Is it even a good idea? What ways can you rig a set of doubles on your back, and why would you do it?

You don't need doubles per se but you need more tanks if your LDS is far away.
A 2 week supply should suffice as starters.

 

[dvrdv]

Yes, your weighting and wing capacity can change dramatically depending on the set of doubles you use. A set of AL 80s makes for a nice set of doubles. They are cheap and will not overweight you like a set of steels will. AL 80's are floaty though. Depending on how much rubber/dry suit you wear, you may however, find yourself too light at the end of the dive (e.g. will need to wear some additional lead). Steels will typically make you quite heavy. I have a set of Asahi steel 100s. Even when empty, you could anchor a battle ship with those things. For most of my dives I've moved to a set of steel HP 80s. I can dive these with a 7mm wetsuit and be just about perfectly weighted. In a lighter wetsuit, they make me a bit heavy but still easily manageable.

In learning to dive with doubles, there are really two issues. One is just figuring out your weighting and trim, which can be very different from what you're used to on a single tank. Second is learning to handle a second regulator (bungied around your neck) and manipulating your valves. Neither of these are overly difficult. Ideally you just need an instructor or capable mentor to get in a pool or shallow water and help you work it out.

Hay RyanT....
Coupla questions about your HP80's if you dont mind. I bought a set of em because of buoyancy characteristics of steel, for switching to a double set in the very near future, and because i'm really short..... Because i dive wet (cannot afford a decent drysuit ! ) and all the "advice" from "cyberworld" about not diving wet with steel cylinders, im contemplating taking the hit and buying a set of AL80's. If I can just go with my double HP80's and not put out more cash for the AL's and not have to deal with trim weights and weighting issues would be the preferred route. Can I use a 45 lb lift wing for double HP80 diving wet? Is there any advice you could give about diving double HP80 in a wetsuit? Any feedback you can give I would greatly appreciate !