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.
Step 2: Cut the Ballast Off
Step 3: Heat Form the Duck
Step 4: Fill Up the Duck With Spray Foam
After allowing the foam to completely cure, carve out the space for the periscope section of the submarine.
Step 5: Mounting Hardware
Step 6: Extending the Switch
The periscope happens to be the power switch for the submarine. I chose a screw with a large head.
it will be concealed inside the duck, but accessible via a hole, in the ducks back. You want it to come close the the duck shell with out touching it, so you can push it with a key or a small screwdriver.
(yes I'm and old school Mac user)
you may want to take some measurements, with the duck pre-assembled to get the screw length right.
Step 7: Connection
the stud allowing it to penetrate the duck shell and accept the nut that hold the whole thing together. through the hole on the left you can see the machine screw head. this is our power button.
Step 8: Mission Complete
Step 9: Duck at the DeYoung
here's some pictures I took of the Saffron Tower
and a short video clip of the other duck in action