They primarily use Dodge 1 Ton vehicles in 2×4 and a few 4×4, which they try to replace every 300,000 miles. Running gear is totally replaced on the hauling trailers regularly need or not, as it will need it sooner than later and a break down on the road is costly. They have bracing run to the rear frame and front frame behind the bumpers. They use a crane, gantry or fork lift to load / unload.It was done decades ago with boats only on skids bolted to the bed, then a trailer went under those briefly. Eventually the truck frames were rebuilt about 1987 to carry more load and in the later years they started full rigs in 1997 model year and the present system was developed. Prior the that they had two trailers here that were built in house ( It all is) and they pulled those with one tons and fur boat and trailer combos, with 3 engines. The move to rigged boats and 20 225 models required more weight and took the max down to the present 3 boat loads.