A watercraft includes a hull provided with a stern compartment inside the hull, the compartment being closed at least on the bottom by a movable portion of a stern platform arranged at one end of the compartment itself which opens up astern of the watercraft, wherein the movable portion can be lowered relative to the hull into the water where the watercraft is floating. The movable portion of the stern platform shifts with a translational motion along the hull without moving away therefrom.