Summer holidays are in full swing, but how can we travel without polluting? One option is sailing across the Mediterranean. A French cooperative is offering an alternative to flying or taking the ferry with a new sailboat route between mainland France and Corsica. It's a long, slow and expensive adventure, but it's the greenest way to get there. Aurore Cloé Dupuis and Alexandra Renard tested "slow travelling" for us in this edition of Down to Earth.