Abstract: The invention relates to a cover device for at least sectional closing of an underwater opening in a hull of a watercraft, in particular an opening of a transverse channel of a thruster. According to the invention the cover device includes at least one variable-volume hollow chamber lip including at least one buoyancy body, and the at least one hollow chamber lip is shiftable into an expansion state or into a shrinkage state by supplying or removing a fluid, in particular air. As a result of the variable-volume or inflatable cover device a more reliable and simultaneously lower-maintenance operation of the cover device is given. In addition, the invention has a thruster, in particular a bow or stern-thruster, as subject matter.

Abstract: A fin stabilizer for stabilizing watercraft includes a pivotable stabilizer fin and a receiving space for receiving the stabilizer fin. The stabilizer fin is shiftable from a retracted state in which the stabilizer fin is received in the receiving space to an extended state in which the stabilizer fin extends from the receiving space. Also at least one flexible cover element for at least partially covering an opening of the receiving space, through which opening the stabilizer fin enters and exits the receiving space during retracting and extending, respectively. The stabilizer fin does not contact the at least one cover element when shifting from the retracted state to the extended state.

Abstract: The invention relates to a cover device for at least sectional closing of an underwater opening in a hull of a watercraft, in particular an opening of a transverse channel of a thruster. According to the invention the cover device includes at least one variable-volume hollow chamber lip including at least one buoyancy body, and the at least one hollow chamber lip is shiftable into an expansion state or into a shrinkage state by supplying or removing a fluid, in particular air. As a result of the variable-volume or inflatable cover device a more reliable and simultaneously lower-maintenance operation of the cover device is given. In addition, the invention has a thruster, in particular a bow or stern-thruster, as subject matter.

Abstract: A fin stabilizer for stabilizing watercraft includes a pivotable stabilizer fin and a receiving space for receiving the stabilizer fin. The stabilizer fin is shiftable from a retracted state in which the stabilizer fin is received in the receiving space to an extended state in which the stabilizer fin extends from the receiving space. Also at least one flexible cover element for at least partially covering an opening of the receiving space, through which opening the stabilizer fin enters and exits the receiving space during retracting and extending, respectively. The stabilizer fin does not contact the at least one over element when shifting from the retracted state to the extended state.

Abstract: A fin stabilizer for stabilizing a watercraft against rolling movements includes a main fin configured to be pivoted by a watercraft-side fin drive, a tail fin, and an elastically deformable connection between the main fin and the tail fin, the elastically deformable connection being configured to flex whenever a water force acting on the tail fin is greater than a predetermined amount.

Abstract: A fin stabilizer for stabilizing a watercraft against rolling movements includes a main fin configured to be pivoted by a watercraft-side fin drive, a tail fin, and an elastically deformable connection between the main fin and the tail fin, the elastically deformable connection being configured to flex whenever a water force acting on the tail fin is greater than a predetermined amount.