On the morning of June 6th, 19-year-old Arthur Germain arrived at the rural town of Source-Seine, in between two national forests in northeast France, and said goodbye to his girlfriend, his parents, the town’s mayor, some journalists, and a small group of onlookers as a guitar player strummed a classically French song in the background. Then Germain disappeared into a grove of sycamores and began looking for water. He was embarking on a journey that had, to his knowledge, never been attempted, much less completed: swimming the entire length of the Seine River, all 480 miles of it, from where it begins as little more than a trickling creek just north of Burgundy all the way to the coastal town of Le Havre, in Normandy, where it meets the Atlantic.

On the morning of June 6th, 19-year-old Arthur Germain arrived at the rural town of Source-Seine, in between two national forests in northeast France, and said goodbye to his girlfriend, his parents, the town’s mayor, some journalists, and a small group of onlookers as a guitar player strummed a classically French song in the background. Then Germain disappeared into a grove of sycamores and began looking for water. He was embarking on a journey that had, to his knowledge, never been attempted, much less completed: swimming the entire length of the Seine River, all 480 miles of it, from where it begins as little more than a trickling creek just north of Burgundy all the way to the coastal town of Le Havre, in Normandy, where it meets the Atlantic.