SS Backplate W/ Doubles

[skdvr]

I am wanting to start diving my doubles (Worthington HP 120's) some time in the next few weeks and I was wondering about SS Backplate vs AL Backplate. Would it be worth the weight savings to buy a AL backplate, or should I be just fine with the SS plate. I was considering only filling the tanks to 1500 lbs for the first dives on the tanks as to not be so overweight at the start of the dive. I am not going to be doing any dives where I will use 240 cf of air, and I would like to be able to check them out near empty at the end of my dive.

I know it would only save a few lbs, just did not know if that would make a difference or not.

Phil

[Gombessa]

You're diving a drysuit right? I think most people make the AL v. SS decision based more on trim than weight. With redundant buoyancy, if you can get neutral at 15ft feet, you don't need the ditchable weight you'd carry by going to AL.

For trim, a lot of people in doubles move to AL because their tanks tend to put them head-down in the water. So, by eliminating the SS plate (close to the head), and replacing it with an AL plate and either a small v-weight near the bottom or a standard weight belt, they can shift weight closer to their feet and have an easier time maintaining trim.

[skdvr]

Yes I am diving a drysuit...

So I guess I will just wait on a purchase of a AL plate until after I can dive them and see how it feels. I can always borrow an AL plate to try if I think I may need it...

Thanks for the info....

Phil

[LCF]

Wow -- 120's? HEAVY tanks!

My recommendation would be start out with the plate you have. Recognize that you may have a tendency to be head-heavy to begin with -- Most people are. Some of it is correctable by working with the position of the tanks in the bands, and the position of the plate on your back. But you must always keep the valves where you can reach them, so that limits the flexibility in the equipment department.

Posture does a whole lot of the job. Good trim is nice in singles, but critical in doubles. Your head has to be BACK -- scalp against the isolator if you can. Your hips needs to be straight and your knees bent. Dropping your head or flexing at the hip joint will almost require you be out of trim.

If, despite good posture and all the positioning tweaks you can do, you are still head-heavy (often recognizable because the only position in which you can balance is 30 to 45 degrees head UP), you may have to go to a lighter plate and move weight onto a belt, a tail weight, or an asymmetric V-weight.

[skdvr]

Originally Posted by LCF

Wow -- 120's? HEAVY tanks!

My recommendation would be start out with the plate you have. Recognize that you may have a tendency to be head-heavy to begin with -- Most people are. Some of it is correctable by working with the position of the tanks in the bands, and the position of the plate on your back. But you must always keep the valves where you can reach them, so that limits the flexibility in the equipment department.

Posture does a whole lot of the job. Good trim is nice in singles, but critical in doubles. Your head has to be BACK -- scalp against the isolator if you can. Your hips needs to be straight and your knees bent. Dropping your head or flexing at the hip joint will almost require you be out of trim.

If, despite good posture and all the positioning tweaks you can do, you are still head-heavy (often recognizable because the only position in which you can balance is 30 to 45 degrees head UP), you may have to go to a lighter plate and move weight onto a belt, a tail weight, or an asymmetric V-weight.

Good Info...

Thanks

Phil

[cummings66]

Phil,

My HP120's are in trim with the steel BP but my HP100's are such that I will probably in the next month buy an AL plate so I can move 4 more lbs to my belt and hopefully make my trim more neutral.

I think there's a good chance your HP120's will trim out because they're so long.

As to the partial fill, go whole hog. The exercise will help you get used to carrying the weight and you won't be surprised when you do fill them as to how much they weigh.

[doczerothree]

I can't advise about a B/P, I'm a small guy and SS with the weight of doubles sends me to the bottom, But fill those tanks!!

[doczerothree]

Suggestion: Try repositioning your bands either up or down. I had a problem similar to the one you decribed. It may help.

uote=cummings66;147506]Phil,

My HP120's are in trim with the steel BP but my HP100's are such that I will probably in the next month buy an AL plate so I can move 4 more lbs to my belt and hopefully make my trim more neutral.

I think there's a good chance your HP120's will trim out because they're so long.

As to the partial fill, go whole hog. The exercise will help you get used to carrying the weight and you won't be surprised when you do fill them as to how much they weigh.[/quote]

[cummings66]

I'm a tall guy, the HP100's just can't be moved enough to make the trim right without a lighter tank, if only it was so simple.

I'm going to try an experiement today with them if I can go diving, but to be honest once you run out of adjustment (and I have) then you've got to go to a lighter plate and move weight down lower.

[LCF]

Yes, and sometimes even that won't do it. I never could trim out our 72s to the point where I could be motionless and horizontal with them. It's why I don't dive them any more.