"They are so vigilant about watching everybody and making sure everybody obeys the rules," she said.
But like many people, Bartlett thought spotting a drowning victim would be simple.
"(You picture) people failing around in the water and needing help," Bartlett said.
Life Guard Instructor Richard Bishop said when you're drowning you're struggling to breathe, so you can't yell, and you're trying to keep your head above water, so your arms are straight out, not waving in the air. Lifeguards size up the swimmers right away.
"You look around and you're doing constant scanning and you're going to recognize the kids that are weak versus the kids who are strong swimmers," he said.
He said it's not uncommon for someone to slip under the water and people just feet away may never notice.
"A lot of times kids like to play opossum for the lifeguards too. So in bigger active pools that's something the lifeguards have to spend time on and look under the water and learn to identify the kids long before it ever happens," Bishop said.
There's been some recent controversy on if people should teach their infants water safety. Some say it gives people a false sense of security. Bishop said the sooner you teach the kids the better and there are local courses you can enroll babies as young as 6 months in.