I was not on a cruise, however, I drove to Bayeux for the tour. They have tours specially designed for cruise stops.
Unless you have a very long day, Paris is a long trip. I would definitely try a ship's tour since you will have to allow plenty of time for your return if you are on a private tour. Paris cannot be seen in a day; maybe a post cruise would be better.
"The test of a first rate intelligence is the ability to hold two opposed ideas in the mind at the same time and still retain the ability to function."
F Scott Fitzgerald
Seven Seas Voyager (30nts) - Dubai - Cape Town - Nov 14