Inflating DSMB from QD hose

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

Sorry I wasn't clear. YOU lose buoyancy when you let the air out of your BCD. That loss MIGHT be compensated (or even overcompensated, as you point out) for by the DSMB....if you hold onto it. If you don't or the string breaks, or the DSMB pops/leaks, you will sink. So you need to be prepared to put air back into your BCD, because your buoyancy is now split into two places and one of those places is at risk.

I'm not saying it can't happen, but how many people have had there string break solely due to tension during ascent of the DSMB??
 
I use a halcyon 3 footer as well. I shoot it regularly from depth (40-150 feet) on drift dives. I do it on exhale into a closed system.

When doing recreational, lazy, drift dives (cozumel/jupiter) I might keep my drysuit hose to use on but I had a scare in my early diving career with a hollis SMB that would not disconnect from the hose.... it caused a bit of an uncontrolled ascent from 40 feet to the surface..... No injury as I mitigated the risk with counter kicking and continually trying to keep my lungs purged, but it put enough gremlins in my head to never consider that method when on a deep dive.

There was something about that Hollis SMB that could get snagged. The Halcyon doesn't snag like that... but the gremlin in my head remains...
 
I usually dump air from my BCD because I hold on to my spool during the ascent of the safety sausage. I have never launched below 40'.
I've done that with my Carter CBPF-35 from 90+ feet multiple times and it works just as well as at 40 feet. IF You have your technique right, there is no dip, lose buoyancy, nothing. Inflating the DSMB from the BC doesn't significantly change your buoyancy unless you spill a bunch of air into the water or otherwise have poor technique or an equipment failure. Adding another dedicated hose or detaching hoses to inflate a DSMB just seems like increasing the risk of task overloading or equipment failure.
 
I'm not saying it can't happen, but how many people have had there string break solely due to tension during ascent of the DSMB??
Not many, probably. But how many have lost their grip on the whole thing during the initial part of the ascent, especially?
 
I found the cylinder such a faff that I converted the DSMB to hose inflation, so much easier
Horses for courses I guess

I'm on my 3rd now - the dsmbs only last about 2 years here before the heat breaks down the internal gas coating (and they fade) but by that time it's had 100-200 launches

I'm so practiced that it's instinctive and done without thought - which is good as sometimes we're caught in strong currents and my mind in on other more important things.

When I travel I take a conventional bottom inflate because it'll be rare for me to send it up - being lazy and letting the guide do it
 
Not many, probably. But how many have lost their grip on the whole thing during the initial part of the ascent, especially?
This. I had a reel get snarled and suddenly get pulled from my grip. Adding air to my wing dealt with buoyancy, but not the sheepish feeling while tracking down the sausage and reel on the surface.
 
I'm not saying it can't happen, but how many people have had there string break solely due to tension during ascent of the DSMB??
#24 braided nylon has a test strength of 250lbs. Even if you cut that in half to account for knots and being wet, 125lbs is way more force than you can exert midwater. So unless you massively abrade the line your risks lie elsewhere - dropping it or getting tangled in it being by far the two most common.
7007_14814_large.png
 
#24 braided nylon has a test strength of 250lbs. Even if you cut that in half to account for knots and being wet, 125lbs is way more force than you can exert midwater. So unless you massively abrade the line your risks lie elsewhere - dropping it or getting tangled in it being by far the two most common.
View attachment 621062

I was thinking about rot in the line over time.
 
I was thinking about rot in the line over time.
Unless you leave it out in the sun or in acidic water, nylon doesn't rot.
 
https://www.shearwater.com/products/perdix-ai/

Back
Top Bottom