B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
B63H—MARINE PROPULSION OR STEERING
B63H5/00—Arrangements on vessels of propulsion elements directly acting on water
B63H5/07—Arrangements on vessels of propulsion elements directly acting on water of propellers
B63H5/16—Arrangements on vessels of propulsion elements directly acting on water of propellers characterised by being mounted in recesses; with stationary water-guiding elements; Means to prevent fouling of the propeller, e.g. guards, cages or screens