Cat Trax are the original catamaran beach dolly. Two large low-pressure pneumatic tires with a long aluminum pole passing through them and extending past each tire. You set the hulls on the ends of the aluminum rod so the boat is nuetrally balanced fore-and-aft and tie it firmly in place. Then grab the bow, bridle, or forward beam, etc. and roll it down the beach to the water's edge. I can load my 400# G-Cat onto the wheels and one-handedly roll it to the water by myself. I'm only 5'10" and 145lbs.

To "Cat-Track" is a term derived from the above product. It simply means to roll the boat around on a dolly similar to the one mentioned above.
It's the same as when someone says they are going to "Zerox" a page. What they mean is they are going to make a photocopy, but since Zerox made the original photocopy machines, the phrase stuck.