does the guy currently have it on a trailer or is it in the water? 16ft glass boat with 65hp is gonna be HEAVY to try and move by hand...probably not doable.
It would be easiest to put it into the water to transfer between trailers. I've never heard of anywhere that rents them, as I can't see it being a popular rental. Most people with boats have them on trailers...
http://edmonton.kijiji.ca/c-cars-veh...AdIdZ493678109 your best bet would be something inexpensive off kijiji.
If you dont want to do that, you could try it on a flatbed uhaul trailer...I know they have some car haulers that would be long enough. The problem is what will you do with it after you pick it up? Its going to be too heavy to move around by hand...