Shuffling by the Impressionist masterpieces in lockstep with the tourist horde wasn’t the Paris morning I’d planned. The d’Orsay was packed with people even though I’d arrived shortly after opening.

When most people think of a barge, they envision a flat-bottomed boat that hauls goods down a waterway – a working vessel. So when I told family and friends that I was going on a barge cruise in ...