Hollywood makes drowning look very dramatic. Take a few minutes to educate yourself what real drowning looks like in this article.
This is what my friend Janet S. had to say when I posted this on Facebook: "It's scary. People sometimes just quietly go under. I know of a child that almost drowned in a pool full of people with lots of adults supervising. When they cleared the pool, she was floating under water. Thankfully they were able to revive her and she's had no long term effects."
Please heed her warning, and keep an eye on your loved ones.