In France, river navigation is booming. Today, it is the least polluting means of transport and the most respectful of the environment. It has become a real alternative to road transport. More and more young people are attracted to this very particular way of life. To embark on this path is for them a real adventure. Allison, Valentin, Jérémy and Clément are four young sailors' apprentices. One week a month, they take courses at the CFA in Internal Navigation. The rest of the time, they sail on the Seine, twenty-four hours a day, aboard a ship transporting goods or passengers. Under the responsibility of their apprenticeship master, they learn the trade in the hope of one day becoming owners of their boats.