For many years, they have made racks to load a small aluminum fishing boat onto the roof of a small camper shell (the kind that are cab height) to load a 12' to 16' long boat onto the roof. This could also be used to load the boat onto the travel trailer roof if desired, but unloading into the water would be more difficult.
However the size of boat loaded on that truck would not work so well. Yes it would be possible to have a rack that lifts the whole boat trailer onto the back of a pickup. Just a matter of engineering it. However it would be a heavy rack, and your 1/2 ton truck probably would not have the capacity to haul the 4,000 pound boat and trailer, rack, passengers and still have enough cargo capacity for your travel trailer's hitch weight.
The dually F-350 has around 5,500 pounds of cargo capacity. I think the highest that the Ecoboost F-150's get is around 2,500 pounds of cargo, including passengers and any options.
It sort of reminds me of a dovetail trailer used to haul a car on the back of a 1 ton truck. Back in the 60's, before roll-off towing platforms where the normal tow truck, they where used to haul car wrecks from the accident scene, when a normal front lift tow truck could not do the job. And dovetail trucks where also used to haul race cars to the track..
Fred.
