SS,
There are commercially available foam balls, really like styrofoam dyed and crumbled. Apparently, if you tie them into your bait sacs, it will float.
I tried using bubble pack a few years ago in the bait sac ... it works but damn, it takes forever to cut out one or two bubbles to use.
Cheers,
Alex
... "high water" is when you can fish from your car.