Abstract: The invention relates to a rudder for aquatic craft wherein the rudder member is provided with a fin which is pivotable independently thereof and with a rotor on the front edge of the rudder member and/or between the latter and the fin or between the rudder member and a guide member mounted in front of said rudder member.

Abstract: A lateral thrust control unit for watercrafts having a pair of tunnels which are directed transversely to the longitudinal axis thereof. Each of the tunnels extend from one side of the watercraft to the oppositely positioned side of the watercraft and have at least one drivable propeller therein. At least one pressure-compensating channel is provided near the tunnels and connects at least one of the zones of differing pressure fields created on the sidewalls of the watercraft as the watercraft moves simultaneously longitudinally and laterally to the pressure field of different potential to equalize the pressure differential therebetween and to reduce the resistance to the lateral movement. The pressure-compensating channels do not have any propulsion devices therein.