Those are DIR! you've got to be kidding.....

[robertarak]

One of the students in my Fundies class spoke with the instructor about exactally this. The student had back problems and was concerned about training in doubles. My instructor explained that Fundies could be taken using a single tank *with an H-valve*, however they would only be able to achive a "rec" pass. There are several requirements to achive a "tech" pass in Fundies, one of which is the use of doubles.

 

[TSandM]

There were six of us in my Fundies class, and I believe we were all in single tanks with standard K valves. I think people would be much better served by taking the class earlier in a single tank, rather than trying to do their own transition to doubles (which usually screws up one's trim, even if one has it rather down in a single tank, at least for a while) in order to get the "tech" pass the first time through. This is not as much of an issue if there are a lot of senior DIR people around to mentor, and I do understand the problem of having to import an instructor and not wanting to have to do that twice. But transitioning too early to doubles, without adequate supervision and feedback, tends to create a lot of bad habits that are hard to eradicate later.

 

[jeckyll]

IMO, if you have excellent buoyancy, trim and good control in the water, doubles are fine for fundies (if you dove them a few times before to get the hang of them). If anything they give you a more solid platform.

That's what I found anyway

 

[deepstops]

I did Fundies in 2002 in a 3mm wetsuit diving a single LP 120 with an H-valve. The cons were well discussed but that set-up was not verboten (then).

I don't dive h-valves anymore (just didn't like the difficult hose routing).

 

[Reg Braithwaite]

There were six of us in my Fundies class, and I believe we were all in single tanks with standard K valves. I think people would be much better served by taking the class earlier in a single tank, rather than trying to do their own transition to doubles...

I have every intention of doing fundies in a single tank with a single valve this coming Summer. Absolutely zero reason for me to fool around with doubles at this point. Following the philosophy of DIR suggests (amongst other things) not spending money on things you don't need if that takes away from things you do need.

So in my own case, if I woke up with money for doubles and a new big wing, I might ask myself whether I would be better served upgrading my dry suit to a DUI or purchasing a can light. Likewise, if I have time to learn the more complex valve drills and protocols for handling the nine failures, I might ask myself if I would be better served investing that time upgrading my trim and buoyancy from the minimal standards outlined in the DIR book to the advanced standards.

Again, that's just me and I am thinking K not Y or H. Every time I think of the additional expense of an H valve and an extra first stage, I ask myself why I would want to find myself stuck half way between the simplicity and affordability of a standard single and the function of a standard set of doubles.

 

[TSandM]

Reg, you are going to love DIR diving. You have the right kind of mind for it!

 

[ppo2_diver]

Reg, you are going to love DIR diving.

Absolutely!!!

 

[lamont]

Again, that's just me and I am thinking K not Y or H. Every time I think of the additional expense of an H valve and an extra first stage, I ask myself why I would want to find myself stuck half way between the simplicity and affordability of a standard single and the function of a standard set of doubles.

When you do start diving doubles, if you don't exclusively dive doubles, then you'll be faced with a choice of dedicating regs to singles, using Y or H valves, or fiddling with switching regs between singles and doubles whenever you need to. It isn't a problem until then (and you can always reuse K-valves on stage/deco bottles if you decide to get H/Y valves on your single tanks, so there's no rush to make a decision).

 

[OneBrightGator]

Agreed. I've seen significantly less wear on o-rings, fittings and hoses since I switched my single tanks to H-valves so I don't have to change reg configurations between singles and doubles. I spent way less on some used H-valves then I would have on a dedicated singles reg.

 

[TSandM]

My original regulator was yoke, and even as we have moved into diving doubles most of the time, I leave that regulator as is, because we travel a great deal and DIN fittings are rare in tropical destinations. I could have bought the conversion kit for the reg and the yoke adapter, but it was frankly easier just to buy a set of used doubles regs, which is what I did.