Karl,
Often thought about making the toy hauler you describe. Maybe a little bit smaller. it wouldn't even really be that expensive in the grand scheme of things. Biggest roadblock to all of that it was a hardly any of all the regatta destinations have a place to park/turn around such a rig.
Maneuverability is hassle with that much rig. The trailer is damn near semi size.
That, and the fact you would have to go inside at the Taco Bell, instead of the drive thru. Seems reasonable. smile
It makes more sense to me than doing a coach/bus type RV though and hooking the boat on. You get to where you're going and you are a pedestrian. With a big rv toyhauler, you drop the trailer, and the pull truck is your wheels. A two ton doesn't have any bigger foot print than a four door, long box pickup.