It's not difficult to notice that on a nice day, skates are about as numerous in Central Park as cars. Some skaters are skilled and considerate, while others (let's be delicate) are somewhat less so. And since the activity is practically a year-round one, especially dense in the spring and summer months, and since skating isn't exactly as easy as good skaters make it look, the Central Park Skate Patrol is there to supply not only the finer points, but the basics. Run during the busiest months for skating — April through October — the patrol is one chapter of the International In-Line Skating Association's "National Skate Patrol". The word patrol might be suggestive of police action, but in fact, in the decade since its creation, the patrol has helped prevent thousands of skaters of all levels of ability from chalking up serious injury statistics through its Skate School and Stopping Clinics. There's no statistic for "prevented accidents", but if there were, the Central Park Skate Patrol would be well within its rights to take credit for a pretty sizeable number. Classes at the Skate School are open to all ages (note that kids under 14 must wear a helmet, by law). Sessions run the second and fourth weekend of every month, with beginners' classes starting at 10am on Saturdays, followed by advanced beginners' classes at noon. (On Sundays, 10am beginners' classes are followed at noon by intermediate classes). Beginners' classes provide basic lessons in standing, getting into the "Ready" position, doing the heel stop, making A-frame turns, stroking, and going from the V-walk into the glide. Advanced beginner classes put the focus on improving one's stride and stopping skills, making parallel turns and spin stops, and learning something vitally important for any New York City skater — street skills. Intermediate classes cover improved stroke and glide skills, backward skating, forward crossovers, T-stops, backward "swizzles", and advanced methods of using the heel brake. Advanced classes (which are available by appointment only) provide lessons in more sophisticated maneuvers such as forward-backward transitions, backward crossovers, lunge turns and stops, and power slides. Class size is limited to 12 students. Cost is $20 per student; $35 for a two-lesson package; or $45 for a three-lesson package. Fees are collected prior to each class; cash (in the form of exact change) or checks are accepted. All classes meet at Blades West, 120 West 72nd Street (between Columbus and Broadway) and last about 75 minutes. Pre-registration is highly recommended; to pre-register, call (212) 439-1234, or register online at www.skatepatrol.org. (Note: Helmets or wrist guards are required for classes. Knee and elbow pads are recommended. Skates, helmets and any additional gear may be rented from Blades West). All instructors are certified by the International In-Line Skating Association. Lessons focusing on braking are offered every weekend, from 12:30-5:30pm, from approximately April 15 through October 15, during the patrol's "Stopping Clinics". The clinics, which are free, are located just inside the East and West 72nd Street entrances to the park. Patrollers who roam the park will either assist beginning skaters who are having difficulty, or else direct them to the nearest "Stopping Clinic".