The floating dock is a particular structure being mainly of use to the repair of boats. Contrary to a dry dock (or dry dock), it is about a superstructure which we immerse to let in buildings(ships) there, then which we raise(bring up) over the water to put the dry(flat broke) ship. The system rests(bases) on the principle of roadbeds. The floating dock does not arrange a propulsion system, he can be moved on the other hand from a place to an other one by means of tug boats. Invented in the 1840s by the American engineers Staddort and Gilbert2; they allow to repair ships in places not arranging a dry dock.