The distress alerts were received overnight Saturday and the rescue operation continued until evening.
"During these rescuing operations, 243 people in distress were saved and taken to the quay. They were handed over to border, fire and rescue services of departments in the ports of Boulogne-sur-Mer, Dunkirk, and Calais," the prefecture said.
Earlier this week, the French maritime prefecture reported on 272 migrants who had been saved in the Strait of Dover.