Brittany Ferries offer a fast way to get to France from the South of England and London with their Fast Craft Normandy Express Ferry which gets you to Cherbourg in less than 3 hours. There are two daily crossings as well as a comfortable lounge and on board facilities. Condor Ferries also offer a service to from Portsmouth to Cherbourg.
Portsmouth to Cherbourg is a really convenient route to take if you are planning on driving down to the south of France because it takes hours off of your driving time once you get to France. It also means that you will not have to drive through Paris to reach your destination.
View the link below to check real time prices, availability and book ferries from Portsmouth to Cherbourg with Brittany Ferries. Alternatively see the bottom of the page for alternatives to the Portsmouth to Cherbourg ferry route.