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.
"Carpe diem quam minimum credula postero"
Seven Seas Explorer - Miami - Venice - Mar 2017
Silverseas Explorer - Arctic - Aug 2017
Seven Seas Voyager - Rome to Beijing - Oct 2017
Seven Seas Mariner - Lima to Buenos Aires - Jan 2018
Silverseas Explorer - Siberia - Jul 2018
Seven Seas Mariner - Australia Circumnavigation - Dec 2018