I always assumed my friends who spent their summers lifeguarding had a simple carefree job. I never gave much thought to just how attentive you have to be as a lifeguard. Thanks for putting this into perspective (literally) for the rest of us.
I'd spend every minute counting the kids, making sure none of them were missing. At the camp I worked on, you not only had to worry about actual drownings, but also administrators who would try and "steal" a kid about once a week from unobservant counsellors, then call a waterfront drill where all the lifeguards on staff had to search the entire waterfront for a "missing" camper. Until the drill was over, no-one involved (including the counsellor who had lost their kid, lifeguards wearing masks searching under the docks etc.) knew if it was real, or a drill.
In the 5-summers I worked there, I took it as a point of pride that none of my campers were ever stolen, and I never saw another counsellor have their kid successfully stolen more than once. The shame and terror of spending about 5-minutes thinking, "Oh shit, I might have just let a child die" was a pretty effective motivator.
I was a lifeguard, so I can speak with some authority. Both skills are necessary. Not only do you have to count and track swimmers, but you have to keep mental notes about their abilities, be aware of what they're doing, and imagine possible outcomes so you can identify and react quickly to the actual outcomes. If your attention wanders for too long, especially at a busy place, you can easily lose track of someone. If you lose track of the wrong person, well, buckle up.
Fortunately, there are usually multiple lifeguards on duty with you, you're usually on a strict 10- or 15-minute rotation with them, and one of the stations is the break room. That helps a lot.
Lifeguarding at a camp is at least 5 times more difficult than at a pool, and I suspect that's why they ran drills to keep the lifeguards on their toes. Underwater visibility is usually next to nothing. The lake is usually full of teenage boys. Access to the water is effectively unlimited. There are often a lot of occluders, such as boats and bushy shores.
1) To keep counsellors attentive to the specific children under their care.
2) To give the lifeguard's the chance to practice their missing child search procedures.
It was stressful, and it was effective.
That said, my bosses weren't huge assholes and didn't disappear kids regularly like yours sound like they did. We had drills, but you could tell by the demeanor of the director that it wasn't real.
Plus, it wasn't a secret. We all knew it was happening. If all the counsellors down by the waterfront were being attentive and they couldn't steal a camper, one of the admins would just come up to a counsellor and ask us to take one of our kids, and tell us to go report a missing camper to the lifeguard in about 5-minutes.
Now as a parent, I'd much rather send my kid to a camp where the counsellors are terrified of losing my kid, than one where they're not.
There are many better, more effective ways to ensure you're not going to lose a kid. We did things like count children before/after each activity, run drills at regular (not weekly) intervals, etc.
We also had games where kids were left to run in the forest for multiple hours unaccompanied (variations on capture the flag). The kids loved it, your kid would love it, and the counselors in charge of your kid wouldn't be obsessively paranoid about the exact location of your child at every single moment because that level of attention just isn't necessary.
The point of drills that simulate reality effectively is to get you comfortable enough with taking the necessary actions at the required times that you will not have terror instilled in you. This is why armies around the world all do 'live fire' exeercise and so on, and why companies run BAU or DR failover tests.
If not, then yeah this is a terrible idea.
Really the most worrying part of the whole thing was teaching the stolen kids that if an adult walks up to them and tells them to quietly sneak away, they get ice cream.
The job was sometimes so intense I'd wake up in the middle of the night in a panic because I thought I had forgotten my whistle or someone was having an emergency. Props to anyone who does it. When executed well and carefully, it's not exceptionally hard work but any lapse of judgement for even a moment can lead to disaster.
I had the same waking panics while being a camp counsellor. We'd have 7 day sessions with 3 day breaks in between and quite often those breaks were punctuated with waking up bolt upright to figure out where my kids were. Took a while for that to pass.
Also took a while to remember how to eat slowly (you eat quick, or you don't eat!)