For each 2000 square feet of water surface area or fraction thereof, the operator shallprovide, in readily accessible locations, at least one Ring Buoy, U.S. Coast Guard approved, with a ¼ inch polyethelene rope attached, no less in length than 1½ times the width of the pool. At those swimming pools that are staffed by lifeguards, there shall also be one Rescue Tube located at each lifeguard station. A backboard with straps shall also be readily available at each swimming pool which is attended by a lifeguard. In addition, all outdoor, inground swimming pools shall be equipped with a rescue hook.