purpose of cumberbund

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soupy2

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Hi all,
This is probably a stupid question...but what is the point of the cumberbund? I gained weight and decided to cut the ends of mine off, but they can easily be sewn back on. I did 8 dives in Florida w/o the cumberbund and didn't have any problems. I made sure to tighten the waist buckle straps on my jacket style BCD to keep the tank from slipping, which is probably the obvious answer to my question. I know extenders are available and I will probably engineer an extension into the existing bund strap ends before I replace them. Worth the effort or not really necessary?
 

SangP

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I suppose they were designed to provide comfort against the waist straps as they are rather thin.

However, you don't need them so far. Leave it be.
 

GrumpyOldGuy

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One of the main purposes is to keep the BCD from riding up on you at the surface when you are vertical. If you have no waist, it can be a loosing battle. If its a problem, add a crotch strap like on a BP/Wing setup.
 

spectrum

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It depends on the exact model but in general the cummerbund is what holds the BC chug to your waist and keeps it from riding up. They are usually "depth compensating" meaning they have an elastic element that keeps the rig snug as you descent the wetsuit compresses. For this to work you need to preload it by slapping it together with the elastic extended some. You can do it underwater too but then it sort of becomes diver compensated.

The web strap that usually has Fastex buckle of some sort often includes tied to the front wrap or pockets of a jacket and limits their travel. If you are too tight then it will squeeze when inflated on the surface. If you run it loose then the BC sides flap around like Dumb ears.I suppose at some level it also backs up the Velcro of the cummerbund but it would take a lot to blow one open if the Velcro was well married.

Pete
 

boat sju

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If it makes you feel any better I cut mine off about 100 dives ago and haven't missed all that velcro yet.
 

spectrum

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Geesh, when will I lean not to post while eating a quick breakfast!

It depends on the exact model but in general the cummerbund is what holds the BC snug to your waist and keeps it from riding up. They are usually "depth compensating" meaning they have an elastic element that keeps the rig snug as you descend and the wetsuit compresses. For this to work you need to preload it by slapping it together with the elastic extended some. You can do it underwater too but then it sort of becomes diver compensated.

The web strap that usually has a Fastex buckle of some sort often includes ties to the front wrap or pockets of a jacket and limits their travel. If you are too tight then it will squeeze when inflated on the surface. If you run it loose then the BC sides flap around like Dumbo ears.I suppose at some level it also backs up the Velcro of the cummerbund but it would take a lot to blow one open if the Velcro was well married.

Pete
 

diverrex

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When I used a Seaquest Balance it didn't have a cummerbund, just a waist strap, and I never noticed a difference.
 

fnfalman

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I have used jacket BCs with cumberbunds and I still don't exactly know what they're suppose to do. They weren't depth compensating. They didn't help keep the BC tight to my body.
 

thez_yo

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For those of us who get to put those BCs on in the water, it helps by being something big to grab onto on the BC to quickly and roughly attach it to yourself. Then you can take your time to find the buckles even in the waves while swimming over to your buddies without the whole thing flopping around the whole time.
 

boat sju

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The web strap that usually has a Fastex buckle of some sort often includes ties to the front wrap or pockets of a jacket and limits their travel.
Pete

Good point. If you remove the cummerbund and then don't have enough movement in your waist straps to tighten the bc up, that would be an oops.
 
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