Swimming in my Grandmas pool as a kid was so much fun. But when I was little, and didn't know how to swim, my mom put pool floaty rings on my arms and let me have at it in the shallow end. Well I wanted to be like the big kids jumping in the deep end, so I did. with my arms straight up. Those pool floaties slipped right off and I was at the bottom in a second. Luckily my Grandma saw, jumped in and got me.

I love my Grandma.

First off, good on you from the rescue!

As a parent, I get both sides. It's absolutely horrifying, but so easy to lose focus. You can start chatting, and not realise you're not tracking the child. You can also both assume the other has eyes on them.

It's better to assume problems like this as systematic, rather than personal failures. If a small child has access to the water, they should be explicitly monitored. If you can't (as a group) do that, then they shouldn't have easy access to the water. You can also train children in water safety from a young age. Babies can be taught self rescue from around when they can crawl.

It's so easy to lose focus. It requires constant concentration, at a time when your life has been turned upside down, and you are often suffering from sleep deprivation. A (apparently) calm 'normal' situation and your brain can relax back and switch off from parenting mode.

It's horrifying when you learn about the number of pool drowning deaths a year. It's in the thousands in the US alone.

Basically this exact thing happened to me as a child. I was fine but it is one of my earliest memories. Good job!