After being at sea raiding and attacking Union vessels for 537 days without returning to a Confederate port, CSA Captain Raphael Semmes of the CSS ALABAMA needed to drydock his vessel for much needed repairs.
Hint: Cherbourg was also a very friendly and protected port. No big mystery there.
Yes Cherbourg was so protected a Union Raider sat outside the port for three days waiting for the Alabama to come out and the French could do nothing to move them.
British ports were the far, far, far better option. Alabama would have left via the Irish Sea with no Union ships to worry about. But thanks for playing.