A day at the pool can be fun and safe when lifeguards are on duty.
Aquatics and drowning expert Maria Bella works with swimming pool managers to best position lifeguards and identify potential safety risks.
Using underwater targets and three synchronized cameras mounted to represent lifeguard stands at different heights, they compare the lifeguard’s view from each location.
“We present that information to the pool 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.
In this example of view from the pool’s current lifeguard position of 2½ feet, it is difficult to see two children swimming just under the surface of the water, but at a 6 and 8 feet chair positions, the children are clearly visible.
Consumer Reports Chief Science Officer says this phenomenon is due to glare off the water and the refraction of light, when light bends as it travels from the water into the air.
From a low position at the edge of a pool, light refraction from the water and glare from the sun or overhead lighting can significantly limit the lifeguard’s ability to see all areas within the water.
“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,” Consumer Reports Chief Science Officer James Dickerson said. "The higher up you go, the larger amount of the space inside the pool that is easily visible to the lifeguard sitting or standing at a higher perch."
The American Lifeguard Association suggests that "the lifeguard chair should be 6 to 8 feet in height to give a better overall view of the area the guard is covering."
The association also said that "lifeguard stands should be placed in such a way that they allow for full coverage of the swimming area."
Trained, professional lifeguards play a vital role in water safety. But even when there are lifeguards on duty, a responsible adult should always monitor children.
“So of course, parents should be engaged with your children when you’re at the swimming pool. But beyond that, you should ask the pool management if they’ve ever done an assessment of the location of the lifeguard stands around the pool,” said Dickerson.
The Consumer Product Safety Commission's “Pool Safely” campaign works to reduce child drownings. You can read up on pool safety and download their safety tips at www.poolsafely.gov.