Pesky Deflator Hose

[ccrprospect]

Hello there,

So in my 40 dives up till now, I have had two instances (both relatively recently, last 15 dives) where I struggle to maintain a steady level at safety stop and surfaced for a few seconds. In both instances, I could have sworn that the BCD was completely deflated underwater, but lo and behold, upon surfacing momentarily and exposing the hose to normal air, I was able to deflate some air and went down again!

Could it have to do something with the positioning of the hose? What would be the reason for this conundrum?

P.S. All my dives are at a constant weighting and I usually finish within the same range of air pressure so it is not a weight issue.

 

[tbone1004]

as you ascent, the gas bubble expands so anything left in the bc, however small, will expand so you can dump it. There is a fairly large expansion from 5m/15ft up to the surface, 30%. If you are dumping out of the inflator hose when you are not at the surface or properly vertical, you need to learn to start dumping out of the dump valves by positioning your body so the dump valves are at the highest position in the water column

 

[DiverDownD3]

How is your body oriented when you try to deflate the BCD? It may be a body position issue as you are trying to dump

 

[Scuba J7]

Is your BCD new or used? Even if new, it's possible your power inflator could be slowly leaking into the BCD. To check that, assemble your gear and leave the air on for a few hours to see if it fills your BCD.

Another possibility is your just not getting all the air out of your BCD. Put your shoulder up and if using the power inflator to dump raise it high, have a buddy take a look to see if all the air is out.

 

[JIMMY PHILLIPS]

I also learned recently that the dump valves work much better and in fact, because I am using minimal weight, recent advice to dump all air before even starting ascent made an incredible difference in maintaining safety stop depth and not corking to the top...so to speak. So far, the most useful advice I have gotten. Really helped me.

 

[ccrprospect]

Horizontal to 45 degrees upwards. I fear that if I go vertical, that would only hasten my ascent to the surface.

Tbone, thanks, but could you clarify more: do you advocate using the dumps valves (i.e. pulling on the ropes at the back of the bc) as opposed to use the deflator button? And this should be done in a vertical position?

 

[fmerkel]

It's a bubble, bubbles rise. Whatever dump you use you need that dump to be in the highest orientation. If you are using your hose dump in a horizontal position, that won't be very effective. You will trap some air.
Getting vertical vs. horizontal won't make any difference unless you are going up anyway. In that case horizontal provides more surface area to the water and slows you down a but more...but you are still going up. You need to get rid of that air, including air in your lungs to help out, to stay down.

Use which ever dump you want, that's a preference. Learn to use it properly. Learn to use all of them properly.

 

[tbone1004]

the pull dumps should be used if at all possible. If you are using the corrugated inflator hose, it has to be at the highest position in the water column otherwise it won't dump. You can do that at 45* up angle, but you also have to roll to the side to get it to come out. Much better to go slightly head down and use the bottom dump valves, or if you have a right shoulder dump, go slightly head up and right shoulder up, and dump from that. I use wings that only have a pull dump on the bottom left, so I have to go head down, right shoulder down to dump, but that is the best way to get all of the air out

 

[Scuba J7]

I love my pull dumps, but use caution as they dump faster than the inflator hose.

 

[tbone1004]

I love my pull dumps, but use caution as they dump faster than the inflator hose.

only if you do it wrong.... Best way to use them is to pinch the cord right at the plastic body and with that you get much more accurate control than you do with the inflator, and certainly much more than just pulling on them