When I was a kid my neighbor built a system like you're talking about. I know I've seen one for sale somewhere too. I'll see if I can dig up an old photo or add. The thing worked like a charm. My neighbor was old and used two canes to walk, but still loaded a 12 ft Livingston right from the water onto his truck canopy in about two minutes.


Here you go! http://www.eideboatloader.com/