Be sure to enjoy the video of this operation as modelled on Mark Dance's N scale Columbia & Western:
A few years ago I got a chance to run on Mark's layout— specifically on the Slocan/Rosebery job. It was a lot of fun, and part of the many reasons why I'm looking at car float operations for my own layout.
I may also be environmentally predisposed to liking rail/marine operations as I grew up in Michigan, which featured car float operations between the US & Canada across the St. Clair and Detroit Rivers, as well as "bigger" boats which connected Luddington, MI to Green Bay, WI. The GT/CN ferries ran until 1995, when it was eliminated after improvements to the St. Clair tunnel.
-Dave