advise/entry to technical diving

[qa54]

Hi,
i'm planning to enter techncial diving. I did a try-out with doubles and 1 stage in a pool. However it seems that i have 2 main issuse

issue 1
i cant do any major turns as i can feel the air on either side of the wing will rush to the other side ( i can even hear the air rushing !!!) . This cause much instability.

issue 2
i realize that to dump air from my BC, i have to tilit my body, heads up , to quite an extent - unlike a single tank wing where i can just remian horizontal (or at the most tilt slightly , but definitely not THAT MUCH as a doubles wing) and dump air.


i thought this was due to the pool being shallow so i went out for an OW practise in 6meters and 10 meters water with the same config.. But i still face the same problems !

is this typical ?

[Genesis]

Trim is VERY DIFFERENT in doubles. It'll take a bit to get used to it, but you'll get it.

Who put your tanks together and what are they? Moving the bands (NO PRESSURE IN THE TANKS WHEN YOU DO THAT!) may be necessary if they're not dialed in right. I had to move mine on my HP100s before I got 'em where I wanted 'em (right at the break of the tank)

As for the dumping, yes, you do have to make sure the dump is at the highest point, UNLESS you have an Abyss wing, which has dumps on the bottom of BOTH sides - then you can reach back with BOTH hands if you're "butt high" a bit and dump that way. Essentially every other doubles wing I've seen has a dump only on one side, making this not work so well :)

You'll find as you get the hang of it that you don't have to pitch up all that much, except when you've got VERY LITTLE gas in the wing - then you may need to pitch up a bit more.

BTW, beware the expansion of that gas on ascent - its not like diving a single, as there's more gas weight when you start, and thus more air in the wing. When you go to ascend you have to pay attention; with a single I can come up and only dump gas from the wing every 20-30 feet. Try that with doubles and you'll get a nice runaway ascent, especially in a wetsuit.

Shell drysuits, because they don't change buoyancy with depth (if you dive them correctly) make for a MUCH easier time of it and, overall, less gas in the wing (if you're weighted correctly.)

[Wendy]

What size doubles are you wearing and what size wing? Sounds like your wing may be a little big.

[OneBrightGator]

If you have an interest in technical diving, find a good mentor to help you out with the initial things, such as getting used to diving doubles, correct configuration, so on and so on, and don't overlook the value of taking a class such as DIR Fund. or an Adv. Nitrox class.

Also, my "rule" for new equipment is one at a time, if you've never dove doubles before I would highly suggest not carrying a stage on your first dive with doubles, give yourself a couple dives to get used to them.

Take it easy and enjoy yourself.

Ben

[Genesis]

One change at a crack, and get comfortable with the one you make before you make a second one.

That's a good rule of thumb.