Are BC dumps really needed?

[wallacm]

I dive a BP/W or a back-inflation bc. They have a pull dump on the bottom left side, my dive profiles are usually bounce around in depth because of the cave system. I find that in a horizontal position, I can control the amount of air to be let out of my bladder much more efficent with the pull dump than the inflator hose. Since in a cave system and trying to keep your feet as far away from the floor as possible, the bottom pull dump is usually the highest point on the bladder, yes you can make the inflator hose higher, but it takes much more effort. And in diving, effortless is key.

And as far as the pull dumps on the corragated hose, yes that is a major fail point, the pull dumps with a string on them on the bladder themselves, much more effective than the corragated hose imho

 

[String]

I read a comment of BSAC (?) when I googled bc dump valve... a british member said that he and his diving buddies cut the cord off their dump valves as ?? something to do with their being caught in the open position??

Thats an individual diver not agency training. It MAY at a push avoid a snag but given where they are its rare. Also diving in britain with thick 5mm gloves or mitts and usually numb hands finding a knob on the end is easy enough. Trying to feel for a bit of string with nothing on the end is nigh on impossible - you dont have the sensation in the hands to allow it.

He claimed that he has more control over how much air is vented off by using the corrugated inflator hose... thus has better control of his ascent ??

I'd put that down to not knowing how to use it. Like anything it takes time to get a feeling for how long to have a toggle pulled to get rid of the amount of gas needed. Toggles do dump quicker than hoses so if you get it wrong you can often dump too much. Its nothing practice wont cure though and once you get used to it you dont need to be reaching for hoses, twisting body position to elevate it and so on.