StLTpr,
I had very good success with rat floats a few years back when my favorite marshes actually had rats in them. I still have about fifty or sixty of the floats I made several years ago, and although they are not quite as productive as feed bed sets in my opinion, the ease with which you can set and check them more than makes up for it--but this comes with one warning--I only trap rats out of my boat--if I were walking a marsh rather than boating, I would leave the floats at home.
I make my floats out of 1/2 plywood, and I have used treated, untreated, OSB, and pretty much anything else I could scrounge up. I rip the plywood into 8" x 16" pieces, then I rip 1 1/2" strips of plywood @ 16" long and screw these to the sides of the floats, so that there is a substantial lip on each long side of the float. Then I cut styrofoam to fit the bottom of the float and glue with liquid nails or other construction adhesive. Almost any foam will work: blueboard, celotex, etc, as long as it doesn't absorb water. To finish it off, I cut a 2" hole in the very center of the 8"x16" float with a hole saw, and drill two small holes in the right hand side of each 1 1/2 lip to attach wire to also.
When I take these out to set, I simply push a small diameter stake through the hole in the center, wire a trap to each end with about 10" of wire, and apply a healthy amount of lure onto the stake. (Asa's muskrat lure is great!) With the 8" width, you can wedge the trap solidly between each of the lips that stick up--and this works with almost every size of #1 leghold. Once a rat hits the pan, the trap dislodges itself, the rat goes over the side, and the other side is left operational. I can set these anywhere there is enough water to drown a rat, they adjust themselves to varying water levels, they are easy to check and extremely easy to set. The last yer I used them, I pre-wired all of my traps onto the floats and loaded them into the boat. I set about 140 rat traps in about 1/4 the time it would noramlly take me to set feed beds.
Good luck--hope this helps.
