The invention involves a double trim tab for watercraft in which connection the flow interceptor (1) is activated by an actuation cylinder (4) and the flow interceptor (1) activates the bottom tab (2). One of the tabs may have a course correction device (10) or a course correction fin (11). In addition, an electronic steering device (14) can likewise carry out a course correction in the event of a trim change in which connection the steering wheel (17) is kept neutral by means of an uncoupling device (18).