Inflating DSMB from exhaled gas

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You literally said reels are less safe. That absolutely means the same thing as "it's more dangerous." You said many people have had runaway ascents due to reels, ridiculously overstated. Have there been cases where it's happened? Absolutely. Have there been cases where spools have done the same? Absolutely. If you're speculating based on hearsay and you don't know why you do something, you probably should not comment. Especially, you shouldn't try and pass it off your comments as gospel because you've taken one fundies course.

Here's a dirty little secret about fundies, it doesn't bestow upon you all the knowledge and experience of the entire scuba diving world, despite what many fundies students would like people to believe. You'd be hard pressed to find a real GUE (read that as done something beyond fundies) that will tell you that they knew everything after their fundies course, because they realized that they had a mountain more to learn.

If you can't think of any reason why you would lock off your spool while holding a stop, you don't have enough experience to be commenting about why you shouldn't. Check out the ISE video, 4:30ish in, Achim locks off his spool. Huh, a GUE Tech II instructor locking off his spool. Check out "SMB Deployment V2" on youtube, Clare Gledhill, another GUE isntructor, locks off her spool around the 2:30 minute mark. That's 2 GUE instructors that do it. Not to mention the myriad of videos of other demonstrations from other instructors from other certifying agencies, recreational and technical. A thinking diver (that's a large part of what fundies tries to instill) would easily be able to think of several reasons why it may be appropriate, even at a recreational level.

I guarantee your GUE instructor locks off spools too. Ask your instructor when and why if you can't think of any. Until then, I'd recommend that you reevaluate your position in the hierarchy of knowledge, and refrain from trying to make bold statements that are beyond the scope of your experience level. This is a habit, and it's not a great one when surrounded by the level of experience of some of the posters on this site.

I get it, you're proud you passed fundies (rec or tech pass?) and think that gives you some greater level of expertise, but you've seemingly also bought into the old GI3 idea that it's DIR or DIW, and come hell or high water you're going to tell everyone how they're doing it wrong, even if it's a topic you know absolutely nothing about (a rebreather thread comes to mind).... There's a metric boat load of experience on this site, realize that you are at the low end of the totem pole in the grand scheme of things and take the opportunity to learn from others instead of dismissing them out of some misguided inflated sense of self.

While we're at it, so that you know what experience I draw upon, I am a CCR/Cave/Technical diver, certified on multiple units, dive OC backmount, sidemount, and no-mount, with stages, scooters, and DPV's, and whose typical dive time runs on the order of 4-8 hours in everything from warm tropical calm waters to 1 degree black water with current and open water drifting decompression. I haven't done it all, but I've done a bit. And I am by far not the most experienced person on this site. Not by a mile. This isn't a "who's got the bigger dive boner" contest, but you need to understand the level of expertise of those people who are engaging in a debate.
 
It’s not possible to hold a shallow stop in 1m swell without incurring at least +/-0.5m movement, when to let your line out your descending than ascending at the next trough; what’s that doing to your off-gassing.

When I’m doing a 6m stop I let the line run through my hand, or more commonly just ride beside it and watch it bounce up and down.
I agree with you. That’s what I’m trying to say. But a locked reel will make you ascend much more than a loose spool.
 
I agree with you. That’s what I’m trying to say. But a locked reel will make you ascend much more than a loose spool.
Not really, if I'm in some swell I lock mine off at anything from 6 to 7m then I can watch it shoot up to my level on the crest of a wave and drop back down again. Its easy to recover when I'm ready to surface.
 
You're making the same assumptions that he is, that not only the only reels people use for shooting DSMB's are the cheap click-lock style that you see in bargain bins, but that people are incapable of using such reels safely and without issue. I have never had a single issue shooting a DSMB from depth with any number of reels, no matter the style, from click-lock to sidewinder to the classic style like the Dive Rite's. Hundreds of DSMB's are deployed every day around the world with those reels without issue.

Hardly, I use reels and teach people to use reels safely. However there are times you have to let go of them. A classic is letting too much line out and getting it around the winding handle leading to a jam. A perfectly workable reels is so cheap you don’t need to be looking in a bargain bucket.

My observation is that new divers using non locking reels end up letting line escape when it would not have happened with a reel that locks when a finger is released. This is true in the preparing to inflate stage and at the collection on the surface stage. The same can be said of a spool, more care is required.
 
I have come across two types of SMBs. One was just a canvas tube with an open end. I could fill it from my octopus or exhaust from the reg in my mouth. Once filled you had to keep the tension right or it just buckled and fell over on the surface. It was only really any use once you were already on the surface. The second one had an oral inflator valve and a excess pressure release valve. You put a few breaths in somewhere below the 5 m safety stop and let it out on about 6m of line. As it rose it expanded and it was dead easy to keep upright with one hand on the line at the safety stop.
 
OK, let's help the ignorant here. Three decades ago I did my OW certification. I don't recall any mention of SMBs. Just a very few years ago I took AOW. I don't recall much discussion of SMBs, but there was one in the PADI crew pack we got that also had our book in it. I looked at the nice orange tube and put it in the basement. Should I be bringing it out of the basement and putting it to some use (on US NW shore dives)?
 
OK, let's help the ignorant here. Three decades ago I did my OW certification. I don't recall any mention of SMBs. Just a very few years ago I took AOW. I don't recall much discussion of SMBs, but there was one in the PADI crew pack we got that also had our book in it. I looked at the nice orange tube and put it in the basement. Should I be bringing it out of the basement and putting it to some use (on US NW shore dives)?
What you just described demonstrates a major change in scuba over the years. When I started diving, I, too, never saw much in the way of SMBs. Now PADI requires inflating an SMB as part of the OW course. I have said many times that an SMB should be required for dive sites like Cozumel.

Essentially, if there is any possibility that you will be on the surface hoping someone will see you and find you, you want an SMB. If there is any possibility you will have to surface in an area where boats may run over you, you not only want an SMB, you want a DSMB--meaning one you can deploy from below on a line before you reach the surface. O the other hand, an SMB is not much good in a cave. You have to use your judgment as to whether or not a coming dive has any chance that the SMB will be useful, and, if it is, bring it with you.
 
I agree with you. That’s what I’m trying to say. But a locked reel will make you ascend much more than a loose spool.

You got some pretty tough feedback, but your response is more comments that are hard to understand?

If you are on a safety stop (or deco) and are subject to swell, then what do you think happens? Have you used a spool in those conditions - I always use a reel, but with respect to the spool- how is it held loosely? Are you trying to saying that it will deploy line when a wave lifts up the SMB?

When you are bouncing around, you need to try to keep pulling down on the SMB as much as possible so it stays upright. So I would think neither a spool nor a reel are going to release and recovery line at a frequently that corresponds to the swells passing. If a reel is locked and it pulls up too much, just let it go. Unless the visibility is horrible and the wind is 40 kts, the reel will be right in front of you when the wave passes - if you let go of it. No different than a spool that is locked.

Have you used a spool in heavy swell for a shallow stop?
 
My DSMB has an inflator valve; but after one hour in freezing cold water my lips are numb and stiff, and I can't seal my lips around it anymore well enough to inflate the DSMB. I also don't like to disconnect/reconnect my (quite short) drysuit inflator hose. So I use the reg exhaust. My DSMB is also open at the bottom but with a self sealing duckbill valve (self sealing baffle), so that it doesn't deflate through the bottom opening. You avoid DSMBs that are open at the bottom because they loose gas easily and are not suitable for longer deco; but the duckbill valve works for me and keeps the air reliably inside.
Entangling yourself in the line is a frequent problem of beginners with every method. I've seen dsmb line catch valves, dive computer, mask band, secondary reg, ... I think it's not so much about picking one method over the other, but mostly about practicing your preferred method of inflation.
 

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