well NVC unless one of us were crazy nuff to try and make a westy float
or had a spare $100K

http://www.amphibiousvehicle.net/amphi/W/wave.jpeg 

The wave (1984) 
It is an amphibious camper. 

Privatly build sins 1984, this project is never finished.
Powered by a V8 Oldsmobile Tornado 455 cubic inch engine in the rear
Topspeed on land 60 mph on water 14 mph.
It is 32 foot long, it has a hot tub, galley and 6 people can sleep but 22 can have a seat.
The cost over the years has grown to more than $ 100,000 but for that money the owner has a two story boat/RV.