JamaicanMon:
I was wondering if anyone could give me any advice/information on making the move to doubles.
Well, much of the advice seems to be, ‘Don’t do it, at least not just to address high gas consumption.’ This is reasonable advice. But, let’s assume part of the advice you also want is how to go about it. It is an equipment-intensive pursuit (and therefore can be quite expensive), and as several have mentioned, there are a number of excellent threads on SB discussing (?arguing about) the best wings, best regs, best BP, the best tanks (LP vs HP, size, etc.). Definitely take advantage of that information. Battles2a5 also provided a great initial checklist.
battles2a5:
Double tanks, isolation manifold, and bands.
Putting the tank size aside, you will also need tank valves set up to accept the manifold, so even if you already have two suitable tanks, you will probably end up changing out the valves to accommodate the manifold (and the DIN regs).
battles2a5:
2 sets of regs, most preferably w/ DIN connections. You Mk25 is a great doubles reg, but you'll need another set.
Ideally, you will end up with two identical regs, but many people move to doubles with whatever regs they have. Some regs are better configured, in terms of port position, for optimal doubles hose routing than others. Again, use SB threads as a resource.
battles2a5:
BP/W, wing lift depends on use, tanks, and exposure protection. Most use a 45-55lb wing
If you are not already using a backplate and wing, this is a very logical starting point in your equipment evolution. Lots of very informative threads on wing comparison, and lots of ‘vigorous’ opinions on the topic available on SB. You will want to consider wing size (battle2a5 gives a good starting range), and whether the wing is a dual or single bladder, which may reflect whether you are diving wet or dry, or have alternate redundant bouyancy.
battles2a5:
Training- either formally or informally through mentorship. Doubles introduce a lot more failure points and require you to know how to deal w/ issues that may arise. … You are also going to have plenty of gas to get yourself into trouble with, so that should be a consideration as well.
TRAINING is a key ingredient. There ARE more failure points. That shouldn’t dissuade you from moving to doubles, rather encourage you to get the training appropriate for learning what the failure points are, and how to deal with failures when they occur. And, yes, you have more gas to potentially get into trouble with, but you also have more gas to allow you to bring your gas consumption into line with NDLs so you can stay down a little longer, and still remain within no-decompression limits. You will find you need to relearn some things about YOUR buoyancy and trim, and it can be quite frustrating. I moved to doubles because I intended to pursue tech training – primarily because I wanted to dive deeper, and stay longer, but also because I thought it would help me improve my proficiency and precision as a diver. Had already made the move to a BP/W, again with that longer term goal in mind. I had a single HP120, and bought a second one, used. Although I had several regs, and possibly could have used them for doubles, I decided to buy a new set for the doubles – got them at model close-out price, which wasn’t cheap, but at least less than retail. Bought the bands, valves and manifold new, and had my LDS set the doubles, regs and hoses up for me the first time. I then went out to the local quarry and starting diving them, ahead of starting the tech course. I then took them on a couple of coastal charters before starting tech. I was already diving a drysuit, so I learned how to dive my doubles dry. First time I used them wet I acquired a first hand understanding of the term, ‘dirt dart’. So, I started diving them ahead of the training. Possibly a bit risky, but it worked for me. I am still learning. One unexpected downside – one set of doubles is not enough (I now have three, and am still shopping). One set of regs is not enough (now have two and continue to browse eBay). Doubles are simply a new, relatively unexplored, section of that financial deep black hole that divers seem to haunt.
