I ended up buying a pair of duck decoys at the local flea market for $10. These are intended to be used by duck hunters to lure unsuspecting water foul within blasting range. When researching what kind of cheap R/C boat I could find to tear apart and reassemble into the duck, I found the yellow 10" submarine at RadioShack on sale for $20. They are available in two different channel frequencies, so I bought one of each, (excited now that I might be able to make two!). So now all I had to do was figure out a way to connect the ducks to the submarines in a fashion that would allow them to look and float like real ducks.
below are som links i found along the way:
R/C duck with a vengeance and rocket launcher
RadioShack R/C submarine
DuckCam Decoy Intructable
commercially prebuilt R/C ducks
Step 1: Stuff You'll Need
It sank.I decided then, if I filled the duck with foam, it wouldn't matter if it leaked.
Also it would be easier to change the batteries, or add a different accessory, like shark fin.
duck decoy - hollow hard plastic, not wood or rubber.
spray foam - this stuff is messy and hard to clean up
drill, holesaw, all thread stud, hex nut, hot glue gun
This where I should mention a missing step.
Notice in the picture I have used a hole saw to cut a circular hatch in the duck's back.
go ahead and do this first.