SAN ANTONIO – Summer’s here and to cool off, many people head to their local pool. You’re much safer swimming with a lifeguard present, but Consumer Reports is warning that light refraction from the water and glare from the sun or overhead lighting can significantly limit a lifeguard’s ability to see all areas within the water if the lifeguard is sitting or standing at the edge of a pool.
Aquatics expert Maria Bella works with pool managers to position lifeguards and identify safety risks.
Using underwater targets and synchronized cameras mounted to represent lifeguard stands at different heights, she compares the lifeguard's view from each location.
"We present that information to the pool (manager) and then help them to determine what height lifeguard chairs they need and where those need to be placed, so they put their lifeguards in a position where those lifeguards truly can identify a struggling patron, whether they're at the surface, just below it or at the bottom of the pool," Bella said.
Photographs showed that from the view of a lifeguard positioned at 2 1/2 feet from the edge of the pool, it is difficult to see two children swimming just under the surface, but at chairs positioned 6 and 8 feet from the edge of the pool, the patrons are much more visible.
It's physics, according to Consumer Reports' chief science officer James Dickerson. He said the phenomenon is due to the glare off the water and the refraction of light. Light bends as it travels from the water into the air.
"There are whole regions inside the swimming pool where no one or no thing is entirely visible to the lifeguard sitting at the edge of the swimming pool," Dickerson said.
The American Lifeguard Association suggests that the lifeguard chair should be 6 to 8 feet in height to give a better overall view and that stands should be placed to allow for full coverage.
Trained lifeguards can play a vital role in water safety, but adults should still closely watch children in a pool even when a lifeguard is present.