Drew Schumann posted a note to a boatbuilding mailing list describing a great detachable wheel system his father developed for moving small buildings that might be applied to small craft (reprinted here with permission).
"I don't see the absolute need for a trailer when towing a boat. My father developed a relatively simple and cheap system for moving small (and sometimes large) buildings by using a system of turnbuckles, cables and "comealongs" to strap a pair of wheels and tongue to just about anything and hauling it down the road. (Including lights and license plate, which clip on)
My father and I would show up to an auction, and would buy the outbuildings. Often, the seller would snicker and grin, knowing that the tearing down and cleaning up would cost more than the wood was worth. In about 30 minutes, he would be standing there, mouth agape, with an incredibly fish-like stare as his garage went tearing down the road at 45 mph.
The flush-sided Bolger "boxes" appear to be ideally suited for this kind of "trailer?" This sort of rig wouldn't protect the bottom from "road rash", but it would haul down low. We used truck tires on stub axles welded to steel plate, with a wedge welded to the bottom, and a cable with "comealong" permanently welded in between. The tongue could be attached to a painter on the bow. The lights and license would be strung and hung by the stern. Launching would consist of disconnecting the comealong and tongue once you could float.
BTW, I find repacking bearings to be only a mildly loathesome activity, so I wouldn't bother with sealed bearings. Just plan on repacking them after hitting some water, unless you can find something with sealed bearings to use as wheels for free or cheap."
Contact: Fritz Funk (firstname.lastname@example.org)