The law of physics doesn't change based on the plane, but the combination of weight on wheels, tire size, lift at speed, and pilot skill do. Many of you have seen the T-6's skiing on water, ( with rescue divers ready) there is a pic of a C-185 on 6.00's skiing on the web somewhere, also.
The issue really is the benefit of doing it to reduce your takeoff or landing. If you take a look on AK Bushwheels site they have some pictures posted of a beautiful 170 skiing on water.
http://www.akbushwheel.com/Cessna170.html
After a bit of research a loaded Skywagon can't fly slow enough to provide enough lift to keep 31" Bushwheels from digging in, AND reduce the landing roll. In other words, I can land it shorter by simply hitting the shoreline at 50-55mph than skiing at a higher speed to prevent the tires from digging in.
Each plane has a balance, it depends if you are willing to find it!
