I also purchased a cooler to use as a cooking vessel. Instead of using a wire rack to hold the bags below the water, I created a frame made out of 1/2" PVC pipe with a plastic mesh from the craft store attached with tie-wraps. Even though plastic floats in water, the cooler lid pushes the frame below the water level. Also, the PVC frame is tight enough against he walls of the cooler that I can adjust how deep the frame sits in the cooler. I plan on posting some pictures.
I tried to post some pictures, but I am having problems. When I try to attach a file, it never stops "Uploading...". Has anyone been able to post pictures on the "new" forum?