Techiques for the use of doubles

[alexxred]

Hi,

Recently I have got myself a set of doubles with an isolation manifold. I'll be doing an advanced nitrox decompression course soon. However as I've never dived doubles before the first thing I plan to do is to get into a pool and practice using my new setup. Can someone point me in the right direction on finding info so that I can practice shutdown techniques etc. Any input into other drills I should practice and where to find that info would be greatly apprecated.

 

[ppo2_diver]

There are some videos on Fifth D's web site you can check out. If you haven't done them before, I would strongly suggest that you have a buddy there with you. It would really suck if you weren't able to open your valves again at the bottom of the pool. Especially if you are overweighted and can't swim to the surface.

Here's a link.

http://www.fifthd.com/fifthdnew/education/videos.asp?from=education&level=1

 

[VTernovski]

never do a valve drill without first making sure your buddy is watching you. it is also a good idea to first do an OUT of GAS drill with your buddy just to make sure he/she can provide you with gas before moving to a valve drill... other than that, I suggest you take the doubles class that covers all the failure points of a manifold, valve drills, etc... I can't help but suggest you take the GUE-Fundamentals class., with your local GUE instructor if available in your area or travel to the nearest location where GUE classes are scheduled.

 

[ianr33]

Check your trim when the tanks are almost empty (especially if they are Al doubles) they tend to get floaty at the bottom which puts you head down.

 

[Meng_Tze]

...I suggest you take the doubles class that covers all the failure points of a manifold, valve drills, etc...

I didnt know there is a doubles class.......where?

But my advise is two part:

First ensure you do the valve drills with a buddy, or at a place where you can stand up. If you do the valve drills in order, you should not be OOA... but a buddy who can donate is the safest way to go. Maybe practice valve drills on dry land first.

Second: do some weighting adjustments on your rig and just swim around. Get used to the set. It swims differently, is heavier, requires a bit more attention in the beginning (more roll force needed to dump, trim adjustments, inflation/dumping gas is more/less than with single, bouyancy control will have to be re-learned). Once you are used to it, it becomes FAR more comfortable and stable.

Only then you should combine swimming doubles with valve drills in a deep site. Get comfortable first. Ensure you are weigheted correctly. The rest is experience. Just clock the hours... and after a while you dont want to go back.

Good luck

 

[Diver0001]

Hi,

Recently I have got myself a set of doubles with an isolation manifold. I'll be doing an advanced nitrox decompression course soon. However as I've never dived doubles before the first thing I plan to do is to get into a pool and practice using my new setup. Can someone point me in the right direction on finding info so that I can practice shutdown techniques etc. Any input into other drills I should practice and where to find that info would be greatly apprecated.

Just go slow to start with and think about which reg you have in your mouth before you start shutting stuff down. And make sure you open it up again before you change back too.

And don't overtrain it now. Any bad habits you learn now will have to be unleaned during the course. The time to really drill it is after you've learned the right order.

R..

 

[D1V3R]

The "old" technique was to stand in your gear with your masked blacked out and breath off your reg until at an uexpected time your tank is shut off by your instructor at an unknow place, and you have to turn it back on before you "die".

I've never done it this way, but i have practiced turning it on and off out of water

its also good to get in the habit of checking to make sure its opened throuout the dive, you can get ceiling roll-off w/o knowing it

 

[PerroneFord]

I had my first tasted of doubles tonight. I guess because I am so new, I didn't really notice a great deal of difference. Heavier on land obviously, but I trimmed out easily, and buoyancy wasn't an issue at all. Air bubble was bigger so I had to be more careful. I spent 20 minutes picking nuts off the pool floor putting them in a pool skimmer net, trying to remain in trim and stay buoyant! GREAT excercise. Trim changed as the net got full, and buoyancy changed as I got heavier. Also started to roll a bit as I was holding the net in one hand. Excellent introduction to what it feels like with a tank slung from you...

 

[scubak]

I dive Hp 80's and I really like them. I like twins/doubles better than a single tank just for the stability and trim...it works for me.
I haven't taken a "class" in doubles. I was shown and told the drills to practice and do with a dive buddy so that I could get comfortable with my "kit".
Kirsten

 

[bedmund]

When I was doing valve drills early on, I was at about 30 fsw and shut down the right post, breathed the reg down - and for a millisecond, I fumbled the backup around my neck. I'll admit my heart rate increased a bit and I got my focus back like *quick*. I'm not exaggerating when I say I was without a reg for less than two seconds but it definately brought me back in the game.

So, like the others said. Don't practice valve drills without a buddy facing you or unless you can stand up to get to your gas supply.

-Bill