I have suffered from repetetive nightmares since I was younger, and I have calmed down a little...
The nightmares I most often had were about drowning. I watched multiple cartoons (for children) when I was younger, and it often involved a character disappearing from their own stupidity. I never got near any objects under water. I always thought that it was scary to even look at a drain cover.
Around 2007 – 2014, a lot of children died in pool related accidents. It was very popular to write about it in newspapers. But nobody is really bringing it up since 2014, even though it is still happening. From what I know, a 12 year old girl had her hair sucked into a pump after getting close to the drain. There is something terrefying about being stuck underwater and knowing that you will never take a breath again. The reason why I am writing about this, is because I think that no parent should ever see their child's body in the pump room, and that people should be aware of this. You might recognize this dark topic from Final Destination 4.
If a drain cover is missing or broken, then you should tell someone who works there and warn people to not get in the pool. If a smaller drain is missing a cover, then your arm might get stuck in the pipe and you will drown. If a child is stuck in a drain, then it takes more than 5 grown men to pull the poor kid out, because the suction has the same effect as if they were pulling a heavy barbell.
Drains should be checked if the cover is safe, and if the pump might be illegal. Some very scary drains have sucked organs out of human bodies, making the people involved in the accidents unable to eat.
Safer covers exist so that nobody can get their hair stuck, and there should be an automatic feature to turn off the pump if somebody is stuck. Luckily, some pools do have that.
Maybe the nightmares I've had for many years were warnings, because I am a person that does dumb things. And I have almost died many times before.
I know this is dark, but every kid should be taught to never play around drains, regardless if the pump is safe or not.