I use my canoe portage dolly that I built from an old baby bike trailer chassis. Amazing the load we put on it. Positioned in the center and the boat becomes weightless. But it would not work for launching but maybe 2-3 times before it seized up. Probably not helpful enough an idea to warrant a photo effort.
Easy enough to build... mine was made from lumber scraps and two wheels off an old handcart. Threaded steel rod for an axle, two pool noodles secured with line across the top... the boat simply rested on the pool noodles and I used balance to keep the wheeling easy. Dolly stored in the trunk when not in use. Very handy for transporting the boat from car to water's edge, and vice versa. Cheers!!!