SAN ANTONIO -

Summer fun in the water can quickly turn into a nightmare when someone goes under -- and it can happen right in front of you.

Lifeguards are trained to know the signs of distress, but all adults watching kids swim need to know what drowning looks like, and it often looks different than you'd expect.

Anita Pickett still remembers some of the advice she got when her kids were in swimming lessons.

"To look for their face and that they would probably be stationary, you know, struggling in the water," Anita Pickett said.

Swimmers who are in distress often stay still instead of splashing around like normal.

"Maybe they might have some flailing arms or not making any progress in the water. Just a basic struggling in the water," Kenny Gonzales, San Antonio Aquatics supervisor said.

But it's not always so obvious. Other signs are staying upright in the water or not having their entire head above water.

Sometimes what people think is a sure sign, is something you'll probably never hear -- a call for help.

"A lot of times it's not going to happen, because they're just worried about breathing, staying above the water," Gonzales said.

Pickett said if she didn't hear her kids, it was time to check on them.

"We were just very careful with them. Always diligent, because that's my pride and joy," Pickett said.

And she's still careful, because the dangers of drowning don't disappear when kids grow up.