Proper BC fit

[Malibugary]

What's the proper fit with a jacket style BC? I have an Axiom I3 Aqua Lung BC and I feel like it's loose after I get in the water. I'm 6'3" and 195. I feel like it's loose and moves around on me while diving. Fits great out of the water. It's a large and I've tried a medium large on in the dive shop and it fits the same on the waist but is noticably shorter on my torso. I feel like I'm trying to pull it down while on dives a lot. Is this an issue or am I just worrying about nothing?

 

[RJP]

I'm 6'2" and was 205 when I began diving. I wore an AquaLung Balance in size large. Seemed right fit.

Silly question... but have you tried adjusting/tightening all the straps? You should be able to get it tight enough that it's "tight enough" to not move around from a size perspective.

You say you are pulling it "down" during yiur dives? Are you vertical? If so, adopting a horizontal trim will certainly help preventing it from riding up.

Also, do you feel like it is the tank moving it around... ie rolling to one side or the other?

 

[triode12]

Can you install a crotch strap onto it?

 

[TSandM]

A BC should fit considerably tighter than you think, to work properly. If you can pull all the straps to their stops, your BC is too big.

If your torso is long, but relatively slender, you will have to go down to a size that may ride higher on you than you would like, in order to get it snug enough to keep the tank stable. This, honestly, is one of the reasons I like backplates with simple harnesses, because you can get a long pattern plate, and size the harness to fit.

 

[g1138]

If you're thin and have no belly your cumberbun has nothing to latch under.

This means that most stock BC's will ride up on you, because even in a horizontal position, you're shoulders are tilted higher and the air likewise will ride up the BC and ride up on you.
Only solution is to get a crotch strap. There's no option for that with the Axiom I3 unless you do it yourself.

Tightening the shoulder straps does NOT tighten the BC contrary to popular belief. All it does it raise the pocket position and limit how high the BC can ride up. But then you can't access your pockets easily unless you're were born a Sea Otter with their awkwardly adorable armpit pouches.

Here was my solution before I decided to learn how to dive a Bp/W.
It works and it's pretty secure to.
I used some neoprene scrap fabric and glued a triglide with Neoprene Cement.
I was then able to thread a crotch strap, once that connection cured.
You could use Webbing and AquaSeal as well.

I can give you more specific directions if interested.
With a crotch strap however you add new hazards to diving, specifically weightbelt placement under or over the crotch strap. There are advantages and disadvantages to both.

 

[tbone1004]

you're really going to be fighting an uphill battle without a crotch strap. For reference, the crotch and waist straps are the only straps that are required to be anything close to "snug" in a harness system like that. Typically the shoulders are quite loose and this has no ill effect on fit or function. You set the waist strap where it needs to be, fit the crotch strap so the tank doesn't tilt up off of your back or ride up towards your head, and snug the waist belt so it is secure and off you are. The shoulder straps are actually supposed to have quite a bit of room underneath them when you are horizontal in the water, this is by far the best fit for this type of system.

For a recreational BC again, you are pretty much SoL without a crotch strap as you'll never get it to be snug enough in the water and work the way it is supposed to especially at the surface.

 

[Malibugary]

What's being described is what's going on. When I gear up out of the water it fits snug around my hip/waist line but I'm out of adjustment. While diving the tank does tilt on me. The top of the tank doesn't touch my head if I tilt it back. Once I the water if I try and look ahead while horizontal it's in the way. I tried the ML size on in the dive shop and it fit the same but felt smaller/shorter. No way I'm getting a M to work. I'll have to see about the crotch strap deal.

 

[highdesert]

You may want to look at Zeagle BC's. They're modular, so you can mix sizes ... one size harness, another size for the 'jacket' part, though it's a back inflate type BC.

 

[tbone1004]

sorry bud, but may just be easier to sell that rig and get one that will work for you from the get go. You're trying to squeeze a square peg into a round hole. Not sure what you paid for it, or if you have the option to return it, but there are cheaper options that will work infinitely better for you....
i3 prices are like $500, a DSS long backplate with wing is $460...

 

[dmoore19]

A crotch strap would be next to nothing. My Zeagle Stiletto has one. I don't think it would be too tough to find a way to put a crotch strap on the BC the OP has.