The canal boat is interesting. However one must keep in mind that the canals on the Continent are much wider than the ones in the UK. With only a couple of exceptions the UK canals limit the size of a narrowboat to 72 feet by about 6-1/2 feet. Be hard to pump several millions into a planform that size unless you gold-plated the boat.
We've been over the aqueduct pictured in one of the posts on several occasions. Pretty impressive considering it was built in the late 1700s/early 1800s and still uses its original cast iron trough to carry the canal.