It sounds as though the 47 inches would be the length of the hull. That's going to require a rather large printer, unless you can accept segmenting and gluing of the printed parts. A fellow makerspace member printed a vessel that was about thirty inches long, split up into ten inch pieces. It's obvious where the joins are located but after sanding and painting, it's invisible (mostly). The segmenting aspect is relatively easy. There are a number of programs that can accomplish it. The makerspace boat builder wasn't comfortable with slicing up his boat model, so I chopped it into manageable sections and he printed, glued, sanded and painted the project.

Do you require special filament or are you happy with PLA? PLA won't take sitting in a hot car without deforming, but otherwise is an inexpensive option.