A method is provided for determining a sail path of vessels on a map representative of a marine geographic area, to perform a turn between a start point and an end point, each vessel having a turn radius, the start point, respectively the end point, being associated with a start, respectively an end, circle, the sail path being curvilinear and composed of arcs and straight segments. The method includes: detecting obstacles likely to interfere with at least one vessel; encompassing obstacles into a curvilinear geometric form; determining a sail path of the vessel by minimizing, under constraints, a cost function comprising: a first term representative of the length of arcs making up the sail path and a second term representative of the length of straight segments making up the sail path, taking into account the start and end circles and the curvilinear geometric forms, and a third term of penalization of distance separating the sail path to be determined, at any point of the sail path, and at least one disturbing object.