First pool dives in doubles - advice please

[Grounded]

Update:

Here's my new observation: Moving the bands up as high as they can go makes all the difference in the world. So does salt water.

I had four dives on the new rig today, and I feel totally confident. I was even told I looked like a "cave diver" with a good hover (I think that was an exageration, but I'll let the compliment feed my ego nevertherless).

Big thanks to my instructor, Wes Gruver, for taking the time to square me away and give me the confidence (and controlled practice) to believe I can safely ride my lift bag up, if I need to.

 

[battles2a5]

Glad you got it worked out. Once you spend enough time screwing around with it, it will become easier. Expect to do a little of this every time you change your set-up (e.g. adding drysuit, new tanks, etc.). Good to see you have an instructor that will spend the time to get you squared away.

 

[Jimmer]

What perfect timing....

I tried out a set of faber fx100s in a pool this past weekend with a thremo 200 bar manifold, highland bands, Zeagle Flathead VI regs, an aluminum backplate, and a Dive rite 44# Trek wing. I found that I was pushed into a pretty strong head down position from horizontal (that, if left alone, resulted in me ending up on my back). I was wearing a 3mm wetsuit.

I, too was wondering if anyone had any tip for balancing things out.

Just a note, the Flathead VI's, are big heavy first stages that will put weight up high. I noticed a change right away when I went from DSV's to Flathead VI's on my doubles. Easy enough to correct, as you've found, but it surprised me just how much of a difference those big first stages made.

Jim

 

[DeepSeaExplorer]

Is it OK to loosen the bands (maybe one at a time?) with gas in the cylinder?

Not a problem...

 

[RiverRat]

More good info, thanks to all. I'll be in the pool this weekend in dryuit etc. to approximate my first OW dives for Adv Nitrox / Deco dives in the quarry. I'll report on how my pool dives go.

Grounded, glad you were able to get squared away rather quickly.

 

[RiverRat]

Well I got in a pool dive and 3 OW dives in my doubles. The pool went very well. Felt a bit "head heavy" but I've learned (from another similar thread) that the feeling is somewhat normal going into doubles. And my trim is going from good to a bit head high which I also understand happens a lot. Now I've got to do several tweaks with gear like figuring out my buoyancy at dive's end with a can light, reel etc. And I'm switching from jets to OMS slipstreams as they fit my boots perfect where the XXL jets are a bit sloppy. Did I also mention that all of this tweaking (aka "new toys") is getting a bit expensive

 

[TSandM]

Believe it or not, head heavy and head high go together. When you have too much weight north of your center of gravity, you will tend to go head down. To combat that tendency, you will rear up to shorten the lever arm that the weight has to push you down. Although it is completely counterintuitive, the solution to both is moving weight down -- Going to an Al backplate and putting weight on a belt, or using a tail weight. Changing from the negative Jets to the lighter slipstreams is quite likely to make the problem worse.

 

[RiverRat]

Believe it or not, head heavy and head high go together. When you have too much weight north of your center of gravity, you will tend to go head down. To combat that tendency, you will rear up to shorten the lever arm that the weight has to push you down. Although it is completely counterintuitive, the solution to both is moving weight down -- Going to an Al backplate and putting weight on a belt, or using a tail weight. Changing from the negative Jets to the lighter slipstreams is quite likely to make the problem worse.

Interesting.....yeah I hope I can make the fins work, they fit like a glove. The XXL jet fins have to go, way too much slop unless I go with Turtles. Already using an AL plate. I added a layer of polypro to the last dive and it made me a bit light (at the end of the dive). So maybe adding a bit to the belt to offset the layer and the fins may help. I'm throwing on the wreck reel too for the next dives as it should be standard gear anyway. Lots of dynamics going on.....

 

[Colliam7]

The XXL jet fins have to go, way too much slop unless I go with Turtles. Already using an AL plate. I added a layer of polypro to the last dive and it made me a bit light (at the end of the dive). So maybe adding a bit to the belt to offset the layer and the fins may help. I'm throwing on the wreck reel too for the next dives as it should be standard gear anyway. Lots of dynamics going on.....

Have you tried XL jets on your boots, just to see if that is a viable option? My XLs are very snug on my (size 10) boots, and a PIA to remove at the end of a dive but work well during the dive. Just a thought.
The dynamics are part of the fun and the frustration. It is an empirical process that never seems to end. I started out in drysuit, double steel 120s, Jets, SS BP with a Super Wing, and felt foot light and out of precise buoyancy control. I went to a H Explorer 55 and was still foot light, so I added gaiters, and went foot heavy. Plus I couldn't manage valve shutdowns without releasing my waist strap and pushing the tanks up with one hand and working the valves with the other. So I moved my bands down to bring the tank weight (and valve position) higher. Now, valve shutdowns are easy and I am close to 'in trim'. But, when slinging deco bottles, I have to re-tweak. I have to tweak for salt vs fresh. This weekend we tried slinging 4 deco bottles for trimix class and that was yet another adventure. If I use my Oxycheq Signature 50 instead of the H Explorer, it produces a whole different set of trim issues. Definitely, keep a log of your configuration with each dive, and document your sense of trim and bouyancy with each configuration. It seems tedious but will pay off in the end.

 

[RiverRat]

Have you tried XL jets on your boots, just to see if that is a viable option? My XLs are very snug on my (size 10) boots, and a PIA to remove at the end of a dive but work well during the dive. Just a thought.

Yep I needed a hammer to put them on That's why I bought the XXL's.
Hoping the slipstreams will work out. They fit my Bare Trek boots perfectly.
They're lighter so we'll see what that does to my trim.