Aquatics facility operators have less than three weeks left to register to participate in the World's Largest Swimming Lesson™. For the fourth consecutive year, the event - scheduled for 11 a.m. (EST) on Tuesday, June 18 - will attempt to set a new Guinness World Record for the largest simultaneous swimming lesson. The current record, set in 2012, stands at 24,873 participants representing 15 countries on five continents.

Here are video highlights of last year's WLSL:

Registration for the event, which is designed to reach out to parents and children with a beginning-of-summer message that learning to swim can help save lives, closes May 19.

The WLSL serves as a platform to help local aquatic facilities and national, regional and state water safety and drowning prevention organizations work together. Supporting organizations include the American Red Cross, the Association of Pool and Spa Professionals, the Centers for Disease Control and Prevention, the International Swim Instructors Association, the National Drowning Prevention Alliance and Athletic Business.

Aquatic facilities, waterparks, swim schools and YMCAs have all served as host locations. The registration fee is $42 and includes promotional materials, participant recognition certificates and water-safety tip sheets.

Here is how one facility, the Roseville (Calif.) Aquatics Complex, is promoting its participation in this year's World's Largest Swimming Lesson: