Want to practice SMB deployment alone - Safe?

[naick]

SMB's are hell's spawn

No matter how experienced you are deploying one, if you don't pay attention even for a sec, it will bit you in the arse. The main difficulty is holding the spool and the SMB in such a way it can easily deploy and you don't get caught in it. Focus on that. Make sure you put just a tiny bit of air in the first few times, so you don't get dragged to the surface. I once saw a mate get dragged to the surface from 15m when he got entangled in his full SMB. Took him 20 sec to surface...

 

[mulla]

Thanks everyone for your input, won't quote and reply to everyone to avoid clutter. But all inputs are appreciated

NWGratefulDiver - Thanks for sharing your experience and to watch out for slack lines. I think I will be trying to do some practice runs with a buddy. Or in a pool if I can tag along with a class or something. Even tho I feel relatively safe under a pier at shallow depths, I am still aware that there might be hidden / potential dangers that I'm not aware of being a newbie. I think I'm one of those "weird" person that wants to polish and improve my skills more than I care about looking at the fishes and various marine life :S I understand that I am probably the minority and don't really want to bore any buddy who might not think deploying a smb for 30 mins straight is called fun. I guess I will have to settle with slowly improving my skills.

String - Good idea about having someone at surface to let the air out. We are normally a 3 buddy team so it'll be good setup. Someone deploying, someone at the surface and someone watching underwater. Everyone will make 2 practice deployments and then switch places, after that we can move on to the "touring" part This will also eliminate constant ascend and decents as well.

Naick - Thanks for reinforcing the point. I did read that we should inflate it enough so it becomes just slightly positively bouyant. Then we have sufficiently inflated it.

 

[Puffer Fish]

Jeezz,,, cant believe some people... loads of hot air and hardly a word of advice amongst any of it...

Look, mulla,

Jump in the water as you are planning, but tie a knot in the dsmb.. make sure its nice and tight so you do not get any air migration.

Then sit under the pier and inflate to your hearts content. The fill in the DSMB wont be much, so you will be able to pull it back down to you, so you can dump the air, and start all over again... just make sure the knot is quite low down on the DSMB...

and before anyone argues, how much air do you actually put in a DSMB at 15 -20m?? hardly any, so, whats the difference??

ky

I use a really large one , and part of the skill is getting a lot of air in it, so it can expand and fill the bag. The difficult part is know how to hold yourself down while putting air in it. So while using a small amount of air would work for most of the exersize, it would miss the really important part.

Shallow water deployment is actually harder to do than deep (but less dangerous), as you actually have to put a lot of air in one, because it will not expand that much.

There is nothing quite like the feeling of sending a 75lb lift SMB to the surface and having the line snag in the reel on the way up.

 

[MXGratefulDiver]

There is nothing quite like the feeling of sending a 75lb lift SMB to the surface and having the line snag in the reel on the way up.

Oooh ... had that happen in one of my early tech classes, coming up from a 160 foot dive. Ended up letting go of the reel and worrying about it when we hit the surface about 20 minutes later. We eventually recovered the bag and reel ... one of the advantages of a big bag is that you can see if from a long ways off ...

... Bob (Grateful Diver)

 

[franny]

Mulla,
I will second what Bob said, it isn't wise to be diving alone with your level of experience. Even in shallow water, it is easy enough for something to go wrong and you need some extra time to develop the skills you need prior to diving solo. On top of that you are thinking about trying to task load yourself at the same time. I would be very cautious about doing that.

Where in Australia are you?

If you diving near the major cities there will be dive clubs around (both shop based and private clubs) that you can dive with, and some will have either pool sessions or dives where skills are practiced.

My final suggestion would be to visit Dive OZ, as there is a strong local scene and good support and information for local divers.

 

[DevonDiver]

Oooh ... had that happen in one of my early tech classes, coming up from a 160 foot dive. Ended up letting go of the reel and worrying about it when we hit the surface about 20 minutes later. We eventually recovered the bag and reel ... one of the advantages of a big bag is that you can see if from a long ways off ...

... Bob (Grateful Diver)

I had the same experience. I was diving in the UK, and deployed a 5' DSMB from 34m depth. During its ascent, the line tangled (birds nest) in the reel. It took me just a second to comprehend that the situation could not be fixed - and I released the reel. In that second, I'd been pulled more than 5m upwards in the water column. If the line or reel had been snagged directly onto me, or if I had hesitated to release the reel - then I could easily have been dragged to the surface, with a very high likelihood of DCS. My buddy deployed his bag instead and we ascended on that. Luckily my bag and reel were recovered shortly after on the surface.

 

[Damselfish]

It may look easy but it's actually pretty easy to screw up and get tangled or dragged up. I've even seen people experienced at it blow it and those aren't the ones the ones they post on YouTube.

Safety issues of doing it alone aside, I think you'd learn more from just deploying the thing on each dive, in a more realistic situation midwater from the depth you would really deploy it from, when you feel you're ready. Stuff like planting yourself on the bottom of a pool or in shallow water, inflating only a little so it's easier to pull back down, or whatever tricks to make it easier to "practice", make it enough unlike the real situation I'm not sure spending a whole dive doing that gains you much anyway. Sure a couple tries like that won't hurt to start, and hopefully you won't have trouble getting a buddy to take a few minutes to do that much, but I can't see whole dives of this gaining you much more. A few tries in a pool could also help some to start, but the pool is even less realistic than sitting on the bottom in open water as you're unlikely to have the water movement that makes this more challenging when its for real.

 

[String]

I had the same experience. I was diving in the UK, and deployed a 5' DSMB from 34m depth. During its ascent, the line tangled (birds nest) in the reel. It took me just a second to comprehend that the situation could not be fixed - and I released the reel. In that second, I'd been pulled more than 5m upwards in the water column. If the line or reel had been snagged directly onto me, or if I had hesitated to release the reel - then I could easily have been dragged to the surface, with a very high likelihood of DCS. My buddy deployed his bag instead and we ascended on that. Luckily my bag and reel were recovered shortly after on the surface.

AFAIK last years UK incident reports 15% of all reported incidents were SMB/Ascent related. That hints the training although compulsory has a long long way to go!

(Then again not helped by the fact the main training agency there mandates it MUST be the alternate air source used to fill it, not exhaust bubbles. Ive see a fair few go up with their octopus stuck in the bag or on the strap)

 

[DevonDiver]

String: I guess you are talking about BSAC? Where is that mandated? (news to me, but I haven't dived in the UK for many years now).

 

[naick]

I think I'm one of those "weird" person that wants to polish and improve my skills more than I care about looking at the fishes and various marine life :S I understand that I am probably the minority and don't really want to bore any buddy who might not think deploying a smb for 30 mins straight is called fun. I guess I will have to settle with slowly improving my skills.

You don't really have to devote whole dives to skill practicing to improve your skills. Just take a few mins practice at the end of each dive. If you launch your SMB at the end of each dive of twice at the end of each dive, you get a fair amount of practice. Launching it doesn't take longer than 2 mins normally. You can do the same with sharing air at the end of each dive etc... Just take 10 mins of every dive and your skills will improve a lot. Then there is no need to devote whole dives to skills and worry about boring people to death.