suggestions for lift bags

[DA Aquamaster]

String once bubbled...
One thing to mention when on about the knots are if there is any sort of current the line wont be vertical so the knots wont be at the depth you expected.

Well...yes and no. If you are using an upline tied, for example, to a wreck, then the bag at the other end of the line will drift down current and you will need a lot of lift to keep the line relatively vertical or else you will need to pay out more line for a more angled ascent. Which also reaches a point of diminishing returns as the longer line imparts more drag and pulls the bag farther under.

But with regard to knots we are talking about knotting the end of the line on your reel 10 or 20 ft from the end. (you can't put a knot 20 ft under the surface on an upline for obvious reasons. ) And with a reel you will be free floating under the bag and there will be very little deviation from the vertical, so the knot will be very close to where it is supposed to be.

 

[Ryukyu-diver]

Thanks to all of that was able to put some light on this situation. The video was outstanding and was just what I was looking for. I had saw this video when I was working with some of the DIR guys in a rescue class back in Okinawa but, could not remember where it came from. It served to re-enforce my belief of using an air nozzle or low pressure inflator vice a second stage or exhaust for the inflation. The video makes it look so easy and I feel that for deco in shallow water (10-30) a spool would be easier to use than my wreck reel. I went ahead with the 100Lb closed bottom bag from Dive Rite, although I would rather use a smaller bag for deco (maybe 50lb) the 100lb will give more options. Thanks again.
Tony