A device for determining the flow regime and/or the direction of a fluid flow close to an element exposed to the flow, such as a sail, includes at least one dog-vane (1). The device further includes at least one flexible strip (2), one region (5) of the strip being fastened to the element (7) exposed to the flow and another region (15) of the strip being free relative to the element, so as to enable the strip and the free region extending substantially parallel to the element to flex, the dog-vane being fixed via one of its ends to the free region of the flexible strip. The device includes conversion element (3, 3′, 3A, 3B, 3′A, 3′B, 3C, 3D, 3′C, 3′D) for converting the deformations undergone by the strip into an electrical signal, relative to a reference position, and processing element (4) for processing the electrical signals.