dump valve question

loudgonzo

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• Apr 30, 2007

• #1

Sorry if I can't come up with a better way to ask this question, but here goes.

Besides on a rapid ascent (runaway ascent?), when and why would you use the dump valves on a BC?

During OW course, we were taught to use the lp inflator hose to vent air from the BC when ascending by holding it in a raised position, and to also use this method when descending.

 

TSandM

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• Apr 30, 2007

• #2

The rear dump can be useful if you are in a horizontal position, because it can sometimes be easier to vent there than to lift the inflator hose high enough to get air to come out; in addition, lifting the hose like that can drop your feet into the bottom, especially if you lift your body at the same time. The butt dump can dump faster than the inflator, too, if you're in trouble.

 

H

h90

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• May 1, 2007

• #3

I only use the dump valves, I use the inflator only to put air in the bcd.

 

J

jon m

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• May 1, 2007

• #4

horizontal (cruising over the reef/bottom) dumping is much easier with the rear dump.... try it!

 

drl

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• May 1, 2007

• #5

New divers are taught to use the inflator to dump air because every BC has one, while not every model has extra dump valves. I almost always use the dump valves except for my final ascent, because I have to get vertical in the water in order to get the silly hose high enough to vent, which sometimes causes me to ascend even more quickly (which is exactly what the venting is trying to avert...)
I can easily use the rear dump while horizontal, and the hose dump (just pull on the hose instead of raising it) by just rolling a little to the right. This works much better for me, but YMMV. Try them all and see what works best for you.

Deborah

 

sambolino44

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• May 1, 2007

• #6

On my BC, the corrugated hose is attached to the front left shoulder, and there's a dump valve on my right rear shoulder, and on the right rear at the bottom. I try to use whichever is highest, and in a normal prone diving position, that's rarely the corrugated hose.

 

parrothead600

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• May 2, 2007

• #7

h90:

I only use the dump valves, I use the inflator only to put air in the bcd.

Click to expand...

I did it this way for a while. The only problem that I had was it is very easy to purge too much air from the BC when the dump valve is used. It is easier to control the amount of air purged if the inflator hose is used.

 

jacksatlanta

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• May 2, 2007

• #8

parrothead600:

I did it this way for a while. The only problem that I had was it is very easy to purge too much air from the BC when the dump valve is used. It is easier to control the amount of air purged if the inflator hose is used.

Click to expand...

Parrothead hit the nail on the head, another reason newer divers are first taught to master bouyancy control using the inflator is because the rapid dumps are just that very rapid. I personally prefer using the rapid dumps as i feel they are more efficient; however your sense of your bouyancy and its changes need to be not only good but excellent to safely and regularly use them. If you've reached that point I say dump away.