First Dive in BP/W

[FishFood]

Alright, finally got in my first dive on my BP/W setup. It didn't go too well.

First problem. I guess I was a bit top heavy. If I stayed still i would do summersalts in the water. Although that was sorta fun, it's hard to get good pictures like that.

I had 8lbs (total, 4lbs each) in weight pouches on the top cam bands, and 6 pounds (total) in weight pouches around my waist. I also noticed my head was resting against the first stage. So, I guess i need to take some weight off the cam bands and move my tank down a bit?

Second problem, the rig kept sliding up. This, of course, made the whole thing very loose and wobly. Time for the crotch strap?


So, other than doing wobbly summersalts through out the dive, all went well Always a good learning experience.

[MLenyo]

ew, i better get some dives in before my AOW with my bp/w.

yeah, i hear the crotch strap stops the rig from sliding everywhere, i'll have to think about getting one. hopefully you get it all straightened out!

[NitroWill]

Sounds like you definitely had too much wait in the trim area. 3/1 waist/trim is usually a good ratio to start at. Keep in mind the backplate adds some ballast so subtract that from your normal weight - on top of that you can probably cut down an extra couple pounds cause of the loss of a lot of bulk.

I would never dive (any rig for the matter) without a crotch strap. Keep playing with it - eventually you will get it *just right*

[jbres1]

I have a few questions for you.
1- How much weight do you dive in a BC ?
2- How high do you have your tank ? I ask because this may be part of the problem , you may be top heavy even without the extra weight on the strap..
3- Why the weight on the top strap ?
4-Did you do a weight check at about 15 to 20 ft. ?

As time goes on you will learn to love the BP/W set up. Its so much cleaner in the water with alot less drag. The first few dives in a BP/W is kinda like learning to drive a stick shift car, ya kinda have to learn the little things.

How easy is it for you to get into and out of your BP/W ? If its easy, then its too loose.
Here are a few good sites for setting up the plate.
BAUE How To Size a Backplate
DIR-diver.com - Adjust the backplate

My first few dives in a BP/W were just about the same as yours, except my problem was that if I stopped I would roll onto my back. I took care of that problem, I got rid of my Steel 120 (the tank was 17#'s negitave when full.)

And as for the crotch strap, its well worth the $10.00 it costs .
Jim breslin

[cummings66]

I think we need to rethink your situation. First you should be able to reach your valves, don't move the tank down enough that they get out of reach.

Second, don't place all your weight at the top of the rig like you did, that's the real reason you're having problems, you're top heavy. Depending on tank it gets worse, take an HP80 and put the weight up high and it's a receipe for this problem.

Generally if you attach weights to the cam bands then you do one on each band so it's spread out, many use a V channel weight which spreads it along the length of the plate and is a better solution.

Generally with a plate you're trim (and that's what we're discussing here) is neutral with just the plate and a small amount of weight on a belt. You adjust it by moving a few lbs of lead here and there until you're horizontal.

What's needed to answer your question fully is;

What is your tank?
What is your exposure suit?
What is your body size/weight?

Generally a BP/W will require anywhere from 5 to 7 lbs less weight than a jacket BCD will, they're often positive and take lead to make neutral where a bp is negative all the time. My Mares Vector V1 was neutral, my bp was -5 out of the gate which meant for me I took off 5 lbs for the first dive. The steel tank took off another 5 lbs so I dropped 10 lbs by switching to a BP and steel tanks.

As the prior poster noted, the wrong choice of steel tanks can also make you top heavy in the horizontal position and make it easy to roll over, I think Faber makes a steel tank as heavy as his was. My steel HP120's are about -11 full because I made the choice as to what I wanted to dive with based on specs.

Use a crotch strap, I don't need one but I still use it. My rig hasn't slid on me to a substantial degree yet. Those links jbres1 posted are the same ones I used to adjust my rig, for what it's worth.

[MLenyo]

does it make any difference if you use a weight belt with a bp/w? (as opposed to weight pockets)

[KGNickl]

Originally Posted by FishFood

First problem. I guess I was a bit top heavy. If I stayed still i would do summersalts in the water. Although that was sorta fun, it's hard to get good pictures like that.

I'm just imagining that. Sounds funny, but at the time I bet it was frustrating

[BobbyWombat]

Originally Posted by MLenyo

does it make any difference if you use a weight belt with a bp/w? (as opposed to weight pockets)

I've asked this question myself. There appear to be a couple schools of thought. Bottom line: no, not really. You are free to choose which you prefer.

A weight belt will keep you from becoming too buoyant if you have to take off your rig underwater. It is harder to ditch, since typically it is worn under the BP harness (this can be seen as a good thing, preventing accidental ditching).

Weight pockets are fine. I haven't been able to find quick-ditch pockets for ~10 lbs that work to my satisfaction. (tried some XS-Scuba ones, and they didn't work at all IMHO). There are quick ditch systems out there that carry more weight than I'm interested in, and cost a lot of money.

If you find some small, quick-ditch weight pockets, let me know.

[BobbyWombat]

Originally Posted by FishFood

Second problem, the rig kept sliding up. This, of course, made the whole thing very loose and wobly. Time for the crotch strap?

With a BP/W, especially a STA-less design, your head will be able to hit the valve, if you look up. Not a big deal, not something that needs to be fixed. If it really bothers you, you could try using a STA, which will set the tank off your BP a bit more (if you are not already using one). When diving, you look DOWN at the good stuff, anyway.

Definitely get the crotch strap, and get your weights moved around. A pool session is great for this since you can be in/out and making adjustments until things feel right.

[FishFood]

Thanks for the replies.

The weight on the top band was from experience with my old BC. Cram the trim pockets full and still have bad trim. Obviously that isn't the case now

I read those links. Good info!

For this dive I used an Al80 w/ a 5mm/5mm Henderson. Im 6ft @ 180lbs. Not much body fat, but some. Looking at my log book I used 22lbs with my old BC. I had 14lbs on this dive and will probably add about 2 pounds on my next dive. So, took off 6lbs. Not bad.

Ive got the tank (now) as low as the top band will allow and can still operate the valve w/o problem.

As for the weight pockets, a lot of people like the XS-Scuba ones. Im not a fan of velcro. I find the Oxycheq pockets to be a better choice. Of course, they are twice the price...

My LDS recommended the OxyCheq weighted STA (-6 lbs i believe) when I bought this setup from them. Would this help the trim or make it worse? My head does hit the valves. Makes it difficult to get certain shots...