Well, the first time I tried to deploy my DSMB many years ago and I had watched videos I made one mistake and that mistake was not permanently attaching the finger spool line to it. I didn't like the larger profile of having that thing hooked up to the spool. So I wanted the DSMB and spool tucked away separate for low profile/low drag and just have the clips to release and then 1 clip to attach the reel to the DSMB and send it.
Well... Anyone who has ever played that game and tried to screw around with all that detaching of 2 components and screwing putting a 2 piece puzzle together under water learned the hard way as I did. I watched my BRAND NEW DSMB deployed from 33' at a perfect 50% inflation go soaring to the surface with no line attached. I watched it soar like a lil kid who let go of his his Micky Mouse balloon at Disney.
So, it's not dead simple but I learned it on my own. If I had asked a DM to teach me he probably would grab that DSMB and spool combine them into 1 simple deployable unit that requires no more than Unhook- Detach-Inflate-Let Go.
I switched the way I have DSMB's and spools attached maybe three years ago. I attach them seperately because I really like my one spool and I use different SMB's for different things and areas.
That is how I hook double enders to the SMB and spool - on the spool, note the brass ring and how the double ender is attached to the line. Someone showed me this way a few years ago after complaining about spools and smb's unraveling after you jumped or rolled into the water - over 500 dives and I have never had one come unclipped or unravel.
This is the order I do things in - it's literally fool proof and simple. I'm just normal diving at this point so I am neutral.
1) I unclip the spool and hold it in my left hand
2) I unclip the smb with my right hand and immediatly clip it to the brass ring
3) My thumb goes thru the spool and my other fingers hold the smb up against the spool
4) I unclip the double ender from the spool (the one I used to clip to my BCD) and clip it to a chest D Ring - no line at all is rolled out, everything is still held tight
5) still holding everything in my left hand, I use my right hand to slip the bunge off the smb. My four fingers are on the bottom of the smb so you can pinch it sort of and have a grip on the bottom of the smb.
6) I flick my wrist to unwind the smb and use my right hand to position the inflator under my finger tips of my left hand
7) again, no line has been unspooled at all, my right hand is free and my left hand is holding the spool and smb - I look up and make sure there is no one above me - there is no rush, no stress, you can dive for hours holding it like this
8) I breathe normal thru the reg, take the reg out of my mouth with my right hand (don't release it, hold onto it) Relax, no rush here at all
9) I exhale into the smb, not a full breath, 75% maybe - the smb and spool are being held just like in the picture m- relax, no rush
10) I put the reg from my right hand back in my mouth, as I exhale thru my regulator to purge it - you are still neutral at this point, I move my four fingers off the smb inflator and and capture the spool loosely between my thumb and index finger while breathing in thru your reg - the smb is off to the surface, the spool spinning freely between your two fingers and you are still neutral.
11) I get my other double ender off my d ring with my right hand and when the line is slowing down, I clip the double ender on the line and wind up some line to get tension on it
12) Depending how deep I am, I gently kick up and roll line up as I go, using the double ender to help. I like to be weighted for slightly negative with no air in my BCD so by 40', I have dumped all my air in my BCD and I am hanging on the spool (like 1-2# negative). I am lazy at the end of a dive and do not want to pay attention to my depth, I wind myself up to 20' and just hang there. The other thing it can do, it can keep your smb pointed up in the air instead of laying flat in the water.
It is the easiest most simple way I have seen to deploy a smb. You can stop at any point before putting air in and not have some crazy mess, you have a free hand to deal with any other problem or item. If I am wearing gloves, like 3mm or better, I switch from a spool to a reel but the deployment is virtually the same. I like that spool, it fits my hand well, wider and smaller are uncomfortable for my hand size.
The deeper you deploy, the fuller it will be. One normal breath, no more is needed - any more than that and you will not be neutral, you will be flopping around and causing a mess. You will never get one full from 30' unless you have a beef jerky size smb - just quit fooling yourself and face the facts. If you must, finish filling the thing at the surface.
