back when i first started working in a machine shop (late 80's early 90's), i built parts for an engineer from m.i.t. who had a patent and was building one. it was a box wing design that was 8ft wd to adhere to d.o.t. standards. that way it could be used as a car that could be driven on the hwy.
it also was amphibious. he designed it so you could take off and land in the water. i even built parts for a small folding mini-bike that was stored on said craft. i worked on & off with him for several years, but moved to another job 5-6 yrs later. never heard if he finished it.