Rolling

[JVM4.0]

My wife and I purchased a couple of back inflate BCs from our LDS. We've been diving them for the last few months without incident. Last time out, my wife told me of a problem she's been experiencing all along, but never said anything about it, blaming it on her relative inexperience with a back inflate BC.

It seems that at depth, with the bladder empty, she has a tendency to roll to the right. It's always the right. We've eliminated her politics as the reason for rolling to the right, but I don't have enough experience with back inflates to give her any other kind of help either. On the surface, the tendency is still there, but not as pronounced.

We've double checked the weights, everything appears to be centered correctly, the tank is mounted securely, and she doesn't dive all dangly. The only thing I can think of is the adjustable straps at the shoulders are too loose.

Anybody else have any ideas?

Thanks!

Jim

 

[The Kraken]

Well, if all of her weight is distributed equally on both sides of her body, then I'd remove a pound or two from the right side and transfer it to the left side.

Also check to see that the weights are placed in corresponding locations on the weight belt, if she's using a weight belt.

If she's wearing, say 8 pounds of weight (2 4# weights), make sure that the weights are placed at the same locations on the body ie - if your belly button is 12 o'clock then your weights should be at 8 o'clock and 4 o'clock, or 9 o'clock and 3 o'clock, or 7 o'clock and 5 o'clock and so on.

The placement of weights at 10 o'clock and 3 o'clock would result in a counter clockwise roation because the weight at 3 would generate more torque because of its distance from the center of mass in a horizontal diving position.

 

[JVM4.0]

That's a great idea, Kraken! It's one of those "why didn't I think of that?"

On the other hand, we don't always have an array of weights available, because of the different configurations we dive. To tell the truth, I'd rather attampt to figure out the "why" and work it out that way, instead of merely compensating for it.

In the meantime, I'll pack another 2 pounder!

 

[OE2X]

Just out of curiousity are both shoulder straps tightened the same amount? If the left is just a bit looser then this may allow the tank to become imbalanced to the right side.

 

[ScubaDadMiami]

Sometimes the wing can trap gas on one side or the other. So, if she is getting forced to the right, that could mean that the wing has gas on the left side. Roll to the left, let the gas move to the other side and then try to remain level. If that works, that was the problem. Just keep doing according to which side has gas in it.

 

[JVM4.0]

So far, you have all presented ideas I hadn't even thought about as yet. This weekend, we are going to take a look at the specific configuration of both BCs. I don't seem to have any trouble with mine, and it may just be that there is a difference in the way the straps are set up. Maybe if I get her to try mine on, and I try hers on, something will become very obvious right out of the box. If not, we can look at the strap configuration and try one thing at a time, until it "feels" right, then into the pool!

Thanks for all the input, and keep 'em coming!

Jim