What do you thnk of pull dumps?

[Dan Gibson]

I used to use one when I first started diving. On my first trip I pulled and the pin came out. I was not aware until after the dive. It was further complicated by integrated weights. On this boat, you can only carry so much weight when they help you into your gear. You had to put the integrated weights in after you donned the BC. Needless to say my SP Superhawk NT (retired) was tough to load the weights yourself and see what you were doing. The first mate loaded it for me (incorrectly). During the dive I kept trying to dump air. I thought I had too much air in my BC. I didn't know that my weight pocket had fallen out. I pulled several times (apparently too hard) and I spent my safety stop hanging upside down to my buddy. I don't use integrated weight pockets or pull dumps anymore.

 

[WreckWriter]

Hose pull dumps are the cause of most BC failures.

WW

 

[Big-t-2538]

we need another category....like....

"I have one, but don't use it"

as opposed to the emergency one. I use mine for class demos when we go over how the BCD works....other than that it isn't used.

 

[scubaredneck]

My ScubaPro BCD has pull dumps on the right shoulder and right hip but not one on the inflater hose. When I have used BCDs with an inflator pull-dump, I have used them. I can see where they might be a failure point but no more than any other pull-dump.

 

[Uncle Pug]

kingprawn once bubbled...
I keep horizontal ... Lifting my hand above my head to dump from the deflator valve is rather difficult in this position, and causes my drysuit do vent.

Your flexibility issue aside... the suit dumping automatically as you raise your inflator to dump it while horizontal is actually a great benefit.

We dive our suits with as much gas out of them as will go and use our wing for buoyancy compensation. On ascent when I hold my inflator hose up (while horizontal) the suit takes care of itself since I have a forearm dump and the wing also adjust itself as only the expanding portion of the gas escapes.

If the goal is finer control then I recommend you try this.

 

[JeffAustin]

There's something about pulling on a hose to make a BC dump that just doesn't seem right. Maybe it's the added failure potential. Lifting an inflator hose to vent becomes second nature, I don't even think about it, I just do it. UP is right (as always!) about drysuit venting, kind of like one stop shopping. If you are in a situation where you need to vent your wing, you probably need to vent your suit, also.

 

[Soggy]

My SeaQuest BC has a pull dump, but I didn't even know what it was or how to operate it until a few days ago. Since my wing has been ordered, I guess I'll never know

 

[kingprawn]

Uncle Pug once bubbled...

On ascent when I hold my inflator hose up (while horizontal) the suit takes care of itself since I have a forearm dump and the wing also adjust itself as only the expanding portion of the gas escapes.

Uncle Pug,

You are right. On ascent, this is exactly what we do. I was referring to venting at depth during the dive.

We also dive with just enough gas in the suit to prevent squeeze or reduced insulation. Often when venting at depth I find that reaching up, gas raises to the left arm and vents unplanned. If I have also vented the BC, I have now vented too much gas. Now I have to put more back in the suite to prevent squeeze. Maybe I just need to adjust my exhaust valve once reaching depth.

By using the pull dump, I prevent this problem. Do you normally leave the inflator hose bungeed to the BC/Webbing? I recently tried a Halcyon Pioneer bp. It is a thing of beauty. Balance and trim were great. I found that if I did not strap down the hose it got away from me. They do provide a nice bungee cord for holding it in place, but I found that made it hard to vent while horizontal. I used the back vent. Is this SOP for this gear? My LDS pros have less experience than I do, so I don't take their opinions too seriously.

Curious to hear your input.

Dave

 

[Uncle Pug]

kingprawn once bubbled...
We also dive with just enough gas in the suit to prevent squeeze or reduced insulation. Often when venting at depth I find that reaching up, gas raises to the left arm and vents unplanned. If I have also vented the BC, I have now vented too much gas. Now I have to put more back in the suite to prevent squeeze. Maybe I just need to adjust my exhaust valve once reaching depth.

By using the pull dump, I prevent this problem. Do you normally leave the inflator hose bungeed to the BC/Webbing? I recently tried a Halcyon Pioneer bp. It is a thing of beauty. Balance and trim were great. I found that if I did not strap down the hose it got away from me. They do provide a nice bungee cord for holding it in place, but I found that made it hard to vent while horizontal. I used the back vent. Is this SOP for this gear? My LDS pros have less experience than I do, so I don't take their opinions too seriously.

Curious to hear your input.

Dave

Yes... if you leave gas in your suit then adjust your exhaust valve... I have mine adjusted - all the way open - I want as much gas out as will go... I rely on my undergarment to keep me warm.

As for the inflator hose... yes I have that run underneath the bungee loop but it is certainly no chore for me to lift that a bit to let a little gas out of the wing... however I rarely would need to do this during the dive unless we were ascending to another level and then it is only a small amount... the rear dump works well for this too.

I have a hunch you are diving with too much gas in your suit for one and chasing neutral buoyancy with the wing/bc inflator button.

I can manage a whole dive with my steel 72 without adding any gas to the wing at all... just using my breathing... it wasn't until a week ago that I added a wing to that backpack and I haven't even had it out diving yet since.

The point is... you can control your buoyancy with your breathing to a great degree... you don't need to be adding and then subtracting gas from your BC on an ongoing basis during the dive unless you are doing a sawtooth profile... which isn't the best to begin with.

 

[kingprawn]

Uncle Pug,

You may be right about too much gas in the suit. I’m still working on my drysuit technique. Normally, I just vent occationally to adjust for buoyancy changes in the tank, and movement up around the wrecks. (Yes a little sawtooth, but I keep the ascent rate low.)

Thanks for the feedback,

Dave