~ National Lightning Safety Institute ~

Section 4.7

Lightning’s behavior is random and unpredictable. We recommend a very conservative attitude towards it. Preparedness and quick responses are the best defenses towards the lightning hazard.

Swimming pools are connected to a much larger surface area via underground water pipes, gas lines, electric and telephone wiring, etc. Lightning strikes to the ground anywhere on this metallic network may induce shocks elsewhere.

The National Lightning Safety Institute recommends the following swimming pool safety procedures:

1. Designate a responsible person as the weather safety lookout. That person should keep an eye on the weather. Use a "weather radio" or the Weather Channel or other TV program to obtain good localized advanced weather information.
2. When thunder and/or lightning are first noticed, use the Flash-To-Bang (F-B) method to determine its’ rough distance and speed. This technique measures the time from seeing lightning to hearing associated thunder. For each five seconds from F-B, lightning is one mile away. Thus, a F-B of 10 = 2 miles; 15 = 3 miles; 20 = 4 miles; etc. At a F-B count of thirty, the pool should be evacuated. People should be directed to safe shelter nearby.
3. Pool activities should remain suspended until thirty minutes after the last thunder is heard. The distance from Strike A to Strike B to Strike C can be some 5-8 miles away. And it can strike much farther away. Why take a chance with lightning?