I’ve written about lightning before and the necessary inconvenience it causes swimmers on a hot summer’s afternoon.
The hand wringing for lifeguards begins when they’re trying to decide how close the storm is and when to clear the pool.
Typically, they’re relying on the ‘flash to bang’ method. This involves seeing a flash of lightning and counting the seconds until you hear the thunder. If you hear it before 30 seconds then the strike was closer than 10 kms and, as a precaution, everyone is ordered out of the water and to a safer area.
A little local knowledge and the weather radar can also help in making these decisions.
However, these days with advances in technology the good ole ‘flash to bang’ is beginning to look a bit primitive. A couple of Councils I know are using hand held lightning detectors.
You mightn’t be surprised to hear that there’s an Australian & New Zealand Standard (AS/NZS 1768:2007) for Lightning Protection. What you might surprise you is that it recommends the use of lightning detection devices to provide guidance on when a workplace or recreational area has become unsafe.
When the lifeguard see dark clouds approaching, she simply takes the device off the wall charger, turns it on and carries it with her. The device is no larger than a mobile phone or two way radio.
Depending on which brand and model, these devices can detect lightning up to 100 kms away. It then uses its own location to work out an Estimated Time of Arrival (ETA) and then the reverse to provide an estimated Time to Clear (ETC). This is provided by text, audible tones or by coloured LED lights depending on the model and some also provide storm trend and intensity information.
These devices, when used in conjunction with an ‘Approaching Storm Procedure’, make evidence based decisions making a breeze, especially when you consider some are under $300.
A quick Google search for ‘hand held lightning detector’ should get you on your way. As usual, do your homework and talk to others who’ve used them. Sounds like a great piece of kit and a lot like due diligence.