Easier SMB Deployment???

[Akimbo]

I thought I would share this experiment. I was watching some non-tech recreational divers struggling to deploy an SMB from about 50'. I think it is fair to say that it takes more skill than most new or casual/infrequent divers have. Throw in cold water, gloves, kelp, and a little current and it gets somewhere between entertaining and ugly.

Granted, they generally don’t need to shoot an SMB for a safety stop… but at least these divers seemed compelled to. The riskiest part is filling the bag, orally or from a regulator, and handling the spool without getting tangled and dragged to the surface. I started to consider a simpler method for divers who will never see a 20'/6M decompression stop.

I removed the 100' of small line from a spool and replaced it with 25'/7½M of 1/8"/3mm line. Instead of letting the line un-spool as the bag shoots the surface, I came up to the 15-20' range and let the spool fall toward the bottom while holding the bag. At that point, I orally inflated the bag and let the line slide through my fingers as it surfaced. That worked except the bag was about half full.

The next test was to repeat without holding the line at all. The current was low-to-moderate. I had no trouble staying next to the line and grabbing it after the bag surfaced. Visibility was 20-30'… not sure if I would try it in 5' vis.

The third test was not holding the line and power-inflate the bag from my regulator. The 5' bag has about 25 Lbs of lift and was blowing excess gas out the OPV before breaking surface… I don’t think I ever filled a bag so aggressively.

So far at least, I find it easier to manage the shorter and larger line. It tangles less and re-spools really fast. Others have probably thought of this, but I haven’t seen it mentioned. I agree that it would be nice if everyone had and maintained the skill to shoot a bag… but they don’t. This exercise makes me question if most divers really need to.

 

[Diver0001]

what you described is exactly how i've seen it done by dive guides in Egypt.

R..

 

[The Chairman]

I teach this skill as part of AOW. I have the student approach the task in this manner:

Unclip the double ender and clip it to the BC.
Connect the line to the SMB.
Unhook the inflator hose from the BC.
Hold the reel and SMB in the left hand.
Fill the SMB with the right hand.
Release the SMB and carefully control the reel with the tips of the thumb and pointy finger (left hand).
Once the float has hit the surface, unclip the double ender from the BC and secure the line on the reel.

I live and dive in warm water (Key Largo) and have no idea how this will work with cold water gloves.

 

[SangP]

Something like this?

Stefan's unique way of SMB deployment.MOV

 

[Peter_C]

I tried what you described with a 20ft line and found it tangled too easily. Your experience is vast compared to mine, yet different.

I have a few DSMB's and found the smaller 3.3ft Halcyon to be the easiest and safest, plus it fits in my pocket pre-rigged to a spool. It also stands upright at the surface, unlike a 6ft bag. The oral inflator is fairly easy to use with half frozen lips. Orally inflating means your lungs are empty as the bag is filled leaving you neutral in the water, while waiting to launch. It takes about a breath and a 1/4 to fill completely. From there a spool with a large center to clear thick gloves, or in my case dry gloves, is pretty easy to control with less entanglement hazard or so it would seem.

 

[DA Aquamaster]

I teach this skill as part of AOW. I have the student approach the task in this manner:

Unclip the double ender and clip it to the BC.
Connect the line to the SMB.
Unhook the inflator hose from the BC.
Hold the reel and SMB in the left hand.
Fill the SMB with the right hand.
Release the SMB and carefully control the reel with the tips of the thumb and pointy finger (left hand).
Once the float has hit the surface, unclip the double ender from the BC and secure the line on the reel.

I live and dive in warm water (Key Largo) and have no idea how this will work with cold water gloves.

It works fine in cold water, just let go of the spool. It will normally just spin and dance a bit on front of you, when it stops spinning reach out, take it and clip the double ender back on to it around the line to lock it off.

The same thing works with a semi-closed or open circuit bag as well - just don't unhook the inflator - depress BOTH the inflation and the dump buttons while holding the inflator under the open end of the bag/SMB.

Shooting a large bag recreationally at the safety stop depth is actually a lot harder than in a technical configuration as, if you are properly weighted, you are neutral at the safety stop at the end of the dive, with no negative buoyancy to work with, so you have to fin down fairly aggressively to get a fair amount of gas in a large SMB.

And as Peter suggests, even if you get a large SMB full, you won't have any negative buoyancy to keep it upright on the surface.

On the other hand, once you are on the surface, a large 6' closed circuit SMB can be fully filled and then clipped to a scooter ring etc, and is readily kept vertical - but you can't make a 3' bag much taller.

 

[Dsix36]

All of this is fine until there is wind or surface current that is dragging your DSMB. You might not be able to grab the line or for that matter swim fast enough to catch up to it either. Just thought I would mention that little issue.

 

[Akimbo]

I teach this skill as part of AOW. I have the student approach the task in this manner:

Unclip the double ender and clip it to the BC.
Connect the line to the SMB.
Unhook the inflator hose from the BC.
Hold the reel and SMB in the left hand.
Fill the SMB with the right hand.
Release the SMB and carefully control the reel with the tips of the thumb and pointy finger (left hand).
Once the float has hit the surface, unclip the double ender from the BC and secure the line on the reel...

That's pretty-much how I see it done except the bag is orally inflated (usually deeper) or people just use their octopus to inflate through the bottom. I find blowing a puff into the bag first makes it a little easier to align and keep from tangling in line (and gear). I didn't bother doing that on these experiments since managing the line became a non-issue.

Something like this?
Stefan's unique way of SMB deployment.MOV

Close, except using a shorter line that is completely unwound before inflating. My thought is to avoid any potential jamming and re-spooling more than is needed.

I tried what you described with a 20ft line and found it tangled too easily...

Hmmm, did you use braided or twisted line? I didn't give it any thought, but braided non-floating line (Dacron, Nylon, etc) is the most tangle resistant line I know of.

…It will normally just spin and dance a bit on front of you, when it stops spinning reach out, take it and clip the double ender back on to it around the line to lock it off....

I didn't bother with a clip at all. The larger line seems to stay put better than the "string" so I just shove it into a pocket while it is attached to the rolled bag. Conceivably (thinking out loud) you could just wrap the line around rolled bag, maybe with a large washer or small fishing weight tied to the end. The spool itself may be unnecessary??? I might try that with ¼"/6mm braided line which is really easy to handle even in mitts or dry gloves. I will probably reduce the length to 20'/6M since the end hangs about a foot deeper with a fully inflated bag.

…And as Peter suggests, even if you get a large SMB full, you won't have any negative buoyancy to keep it upright on the surface...

I have never had an SMB that stood-up unless I went a little negative and hung on. I don't understand how bag dynamics changes by having shorter thicker line. I guess the real question is why have all that line unless you are searching and need to mark something (assuming minimal-to-no-D)?

All of this is fine until there is wind or surface current that is dragging your DSMB. You might not be able to grab the line or for that matter swim fast enough to catch up to it either. Just thought I would mention that little issue.

My test was in moderate current. The wind had no effect since the bag didn't stand up until putting weight on it. Besides, the line was only out of my hand a second or two, between release and the bag breaking surface.

I didn't try this in a ripping current, but it didn't seem to drift away since we were both drifting at the same rate. I would try it a few times in a fast current, letting the unfurled line slip through my fingers, before trying the "let go" method. I think I will try it with a 6' Dan SMB next time for a "worst" case test.

BTW, that radar reflector on the new Dan SMB makes the scope light up big time — way better than any of us expected.

https://www.diversalertnetwork.org/store/home.aspx?id=5

 

[dumpsterDiver]

Palm Beach Scuba Diving with 12 yr old 2010 - YouTube

skip to 40 seconds... no need for a reel. Why take gear you don't need?

---------- Post added December 18th, 2012 at 11:01 PM ----------

or.. skip to 8:25 filmed myself

Helldiver SB2C Plane Wreck Off Jupiter Florida - YouTube

 

[The Chairman]

Too much line free floating around the diver for me. Too easy to get entangled in that mess and go for a ride you don't want.