What am I missing here? These drownings looked exactly what I expected from a drowning: someone going up and down the water, splashing in a disordered manner, unable to swim or to keep the head out of the water.
What do people usually expect drowning to look like? Am I missing some detail that should make drowning more evident to me?
Head erect, more splashing, perhaps a cry for help, and above all, someone who thinks and acts like a human being. You can't tell from the site, but a drowning swimmer is a wild animal. If you have to approach at all, approach with extreme caution and with something to extend your reach.
It may be you aren't surprised because the premise of the site is to identify people who are drowning. You know it'll be happening within a minute or so. In real life, it'll happen with small probability in the next few hours. It's a lot harder to spot under those circumstances.
Oh, I don't claim that spotting a real drowning in real life will be easy, or even in the video: lots of attention and searching is needed and the lifeguard there does an impressive job. I was only wondering about the drowning behaviour itself.
The chosen video sample doesn't match the catchy text.