Omer Atoll + float line?

it hugs the float so it doesn't really move...the only force on it would be the drag through the water and that should be minimal.

the weight would keep it oriented upright...you could also add some beads of a glue to the sides of the float to make a barrier from the weight strap sliding along the float

Why would you bother with that strap and weight if the Riffe and Sporasub inflatable floats have a built in ballast. I know the Riffe has a zippered pocket for the ballast so it can be easily removed, can't remember if the sporasub has a removable ballast.

I thought thy were a lot more expensive. That is the only reason.

I have two for different purposes. This was just a way to take the ra and make it work

If you haven't picked something up yet, check out Fox Floats.
http://www.foxfloats.com
I like the idea of a tire innertube for the bladder. You can patch it easily. That's what I ended up doing with my Omer Atoll float. It's pretty much my beater float now, but gets more use than my other floats, and with the innertube to replace the two crappy pvc bladders inside, it works pretty good..... A bit heavy though.