Change to an AL backplate for Doubles?

[bikefox]

When I did my first dives in my double 108s, I found I was a bit head heavy. My instructor suggested putting some weight on my waist for better trim. It worked great, but now I feel I'm a bit heavy (negative). His suggestion was to move to an AL plate (I currently have a 6 lb steel). This reduces my overall weight and more than likely would reduce how much weight I need on my waist. Makes sense to me, but before I buy the AL plate, I thought I would some opinions.

Thanks

 

[deepstops]

It would help to know if you're diving dry or wet and how much weight (if any) you require to hold a stop at 10' with back gas and deco gas close to empty.

 

[BabyDuck]

and if you are diving wet, is dry anywhere in your near future?

i switched to al with doubles wet, then back to ss when i went dry. ymmv.

 

[bikefox]

I'm diving dry. Typically with heavy (400g) undergarments. No deco gas yet. Right now I need no extra weight with the doubles @ 10' with about 1000 psi, which at this point is as empty as I have gotten them. The problem I'm having is that without any weight on my belt, I'm a bit head heavy. I've read that with time this may work itself out, so I don't want to make any drastic or silly changes. I just thought that moving to an AL plate would allow me to add weight on a belt to move some of the weight lower on my body. I just want to see what others think and see if there are any other issues I might face going to an AL plate.

 

[SteveAD]

I'm inclined to recommend against the al plate. If you haven't done a weight check with near empty tanks, you might find that going to an al plate leaves you underweighted. And it sounds like you have not done enough diving in this config to really dial in your skills yet. Don't make equipment changes when the skills aren't there yet. Also, an al plate will decrease your total weight, but it will not appreciably change your weight DISTRIBUTION, because the plate is pretty much over your center of mass/center of bouyancy.

 

[cool_hardware52]

When I did my first dives in my double 108s, I found I was a bit head heavy. My instructor suggested putting some weight on my waist for better trim. It worked great, but now I feel I'm a bit heavy (negative). His suggestion was to move to an AL plate (I currently have a 6 lb steel). This reduces my overall weight and more than likely would reduce how much weight I need on my waist. Makes sense to me, but before I buy the AL plate, I thought I would some opinions.

Thanks

What your instructor is suggesting is reasonable.

You might also try loosening your shoulder straps a bit to move your plate and cylinders down your back. Make sure you can still reach your valves.

Minimum ballast = Being able to hold a shallow stop with (near) empty backgas.

Tobin

 

[TSandM]

Well, at 1000 psi, you're only carrying a pound and a half of foreseeably usable gas, so your weighting is probably pretty close without weights.

Moving to an Al plate will allow you to use a weight belt, and it does help. That's what I did with my LP85s when I got them. However, it is quite likely that just having some more time in the tanks will solve the issue, if it's mild. I still use my Al plate with my doubles, because I have it, but I put a 6 lb v-weight on it

 

[kanonfodr]

I moved to an AL plate for my doubles, but I dive wet in the tropics mostly and with my steel plate and heavy doubles I would have been grossly overweight. I've heard of other divers needing to make the move as well, lets you concentrate that extra amount of lead lower to counteract the head-heavy tendency. Right now I have a 2lb weight on the back of my crotch strap, works good enough now until I get more practice in.

Peace,
Greg

 

[K Mejean]

I use an Al plate. I had a stainless but felt to heavy in general with my doubles. If your problem is your trim and not your ability to keep your bouyancy then maybe you should adjust your wing up toward you head to distribute it better.
I have had to make a similar change just in the opposite direction. My butt started getting a little heavy causing my knees to drop a few inches so I adjusted my bladder down toward my butt and fixed the situation. If you are in good shape with your bouyancy then leave that alone and just mess with your trim.

 

[David_57]

Actually I would say with 1,000 psi left in your tanks you would be closer to -3LBS per tank x 2 = -6LBS, have you tried adjusting your tank bands and repositioning your back-plate and wing so the tanks sit lower on your back and use the Scuba Pro turtle fins which are negative, I used this method and a little practice (about 5 or 6 dives) to trim my HP 100's which I also use with a S/S back-plate and worked fine for me, having to worry about a weight belt would be my last resort.