Heed the lifeguard please

It was early summer and visitors to Thetford's Treasure Island, a town-owned beach on Lake Fairlee, were ecstatic at the return of swimming in the lake. However a temporary damper was thrown on their fun by a warning that a thunderstorm was approaching. The lifeguard on duty asked the swimmers to get out of the water and seek shelter in their cars till the storm passed. Events took an unfortunate turn when some people refused to do this and argued with the lifeguard.

Quite simply, those individuals were putting themselves at risk. And because they had paid (presumably) to use this town facility, they were also creating a liability for the Town. If they had been injured — or worse — by a lightning strike, the Town could have been found liable for failure to enforce safety measures. It's only when swimmers do not pay to use a facility that the owner of a waterfront does not bear this burden of liability.

A typical lightning flash is about 300 million Volts and roughly 30,000 Amps. Compare that to the household current of 120 Volts and 15 Amps.  It's a sobering statistic.

Being in water when there is an electrical storm anywhere in the area is dangerous for two reasons. Lightning strikes the tallest object, and on water this might be a swimmer. Water also conducts electricity very well, so a lightning strike to another object on the water could still harm a swimmer. There is no safe place in water during an electrical storm.

It may seem that the storm is far away. However lightning can travel many miles from the edge of a storm to hit a place where the storm is not ongoing. This is the proverbial "bolt from the blue" — one of the most dangerous types of cloud-to-ground lightning. According to the National Weather Service,  this occurs usually at the back end of a thunder cloud in the form of lightning that travels outward for a long distance through clear, even sunny sky, before turning to strike the earth. Some years ago Treasure Island acquired a storm warning system for this reason.

Perhaps the people in question felt it was unsafe to be in a car during a lightning storm. The National Weather Service states that the outer metal bodywork of a hard-topped car does protect the people inside if the windows are closed and if people avoid contact with any electrically conducting paths to the vehicle exterior (e.g. radios, CB's, ignition, etc.).  If such a car were struck, the highest point, typically the antenna or the roof, would be the target. The electricity would travel through the vehicle's metal shell, then through the tires which have steel belts, and into the ground. It is common for the antenna, electrical system, and one or more tires to sustain damage. Sometimes the defrosting wires in the rear window attract a portion of the current, causing the rear window to shatter. Convertible vehicles offer no protection from lightning, even if the top is up.

Ideally people should shelter in a large enclosed building that has plumbing and electrical wiring. In the event of a lightning strike, the plumbing and wiring will conduct the electricity more efficiently than a human body. But in an emergency, a hard-topped vehicle is better than nothing. 

However, open-sided buildings are NOT safe, even if they are "grounded.” These include beach shacks, picnic shelters, carports, and baseball dugouts. Porches are dangerous as well, as are metal sheds. And a tent and air mattress offer no protection at all.

Once out of the water, it is not safe to stay on the beach. This point was tragically demonstrated a few decades ago in Maryland when four beachgoers did not leave the beach after a thunderstorm began. Instead they sheltered under their beach umbrella. A lightning strike killed them instantly. 

If there is any confusion about the beach being safer than the water, it is because lifeguards are generally trained to clear the water before the beach. 

So please, don't argue with the lifeguard. We should respect their training and allow them to do their job of keeping the public safe.