This is light work requiring the exertion of up to 20 pounds of force occasionally, up to 10 pounds of force frequently, and a negligible amount of force constantly to move objects, and some medium work requiring the exertion of 50 pounds of force occasionally, up to 20 pounds of force frequently, and up to 10 pounds of force constantly to move objects; work requires climbing, balancing, stooping, kneeling, crouching, reaching, standing, walking, pushing, pulling, lifting, fingering, grasping, and repetitive motions; vocal communication is required for expressing or exchanging ideas by means of the spoken word, and conveying detailed or important instructions to others accurately, loudly, or quickly; hearing is required to perceive information at normal spoken word levels; visual acuity is required for depth perception, color perception, peripheral vision, preparing and analyzing written or computer data, visual inspection involving small defects and/or small parts, use of measuring devices, operation of machines, determining the accuracy and thoroughness of work, and observing general surroundings and activities; the worker is subject to inside environmental conditions, noise, hazards, and atmospheric conditions. Thorough knowledge of water safety rules and of life saving and first aid practices and techniques; general knowledge of the cleaning and maintenance requirements for large pools and related equipment and supplies; considerable skill and strength in swimming; ability to enforce rules and to remain calm under stress; ability to clean and maintain a swimming pool and related facilities; ability to establish and maintain effective working relationships with associates and the general public.