the first 10

[Walter]

You are either kicking or you are not getting all the air out of the BC or both. Some BCs do trap air. Zeagles are good at this. Inflate your BC and the look at the dump valve while you are holding it in front of you in the position it would be when you are trying to descend. Is the dump valve at the highest point? If it's not, it's trapping air. If there a clear unobstructed path for all the air to get to the dump valve? If there isn't, it's trapping air. Figure out how you need to move your body while wearing the BC to solve the problem. If you're using a Zeagle, you need to lean forward and to the right while dumping air as the dump valve is positioned a tad too low on the back of the bladder.

 

[The Kraken]

There is also a little gremlin that prevents a B/C from dumping efficiently, if using the dump on the L/P inflation hose.

Many of the B/C's have a flap that secures the inflation hose to the left shoulder strap of the B/C. If the hose is secured by that flap, and the bend in the hose, when lifted for deflation, is below the highest point of the inflation as it comes over the shoulder, you will have a problem dumping all of the air because of basic physics.

It'd be a whole lot easier to draw this than try to explain it !!!!

Air doesn't flow downwards unless under considerable pressure.

the K

 

[Walter]

Excellent point.

 

[jham2081]

I've experienced exactly what Kraken talked about. How do you guys avoid that. Do you just let your hose float around and don't strap it in?

Also, is there any harm (other than losing cool points) of doing one of the techniques i learned in the pool that snorklers use to get under. Something like "bend at the wast and let the weight of your legs push you down"? Did that make sense?

 

[The Kraken]

Instead of restricting the movement of both the corrugated B/C and L/P inflator hose, simply bungie the L/P hose to the inflator and let it secure the assembly to the B/C.

This allows the corrugated hose to be lifted above the bend in the shoulder and properly dumped.

the K

 

[jham2081]

So the bungie is just around the lp hose and corrugated bc, and is not actually wrapped around the shoulder of the BC strap. The lphose and corrugated hose bungied together is "free floating" except for in the back where it is hooked to the bladder? Sorry, its somewhat difficult to explain in words what I'm imagining.

 

[The Kraken]

Nope. Have the bungie attached to the b/c shoulder strap and the L/P hose.
Let the corrugated hose be free to move.

the K

 

[jham2081]

That makes sense. Thanks for your help!

 

[Freds@Aquanauts]

Hi I'm new to this forum!

Most LP inflators that I have used have a dump valve at the base of the hose as well, that is activated by yanking the whole hose upwards, if when you want to dump air using the hose you do this too you are guarenteed not to have that nasty bend in the hose which prevents the air from escaping.

Freds

 

[The Kraken]

Indeed!
If there is a pull dump located and the 90 degree elbow, all the diver has to do is just pull down on the corrugated hose to make it dump.