For OP's sake, hopefully no older than 5...

I would kick him back into the pool, and make sure he lands on his own turd.

It is your fault lol

Understandable if he's only a child. But if he's in his teens that's troublesome.

I want to know how high the diving board is. If it was a high one then it would have had some serious splash.

If he's old enough to get up on the diving board he's old enough to know better and know that is not acceptable. I think you might want to evaluate the way you are raising your son. You both should be ashamed over this incident.

This FML definitely needs OP to do a follow up!

Maybe drop him at a babysitter next time and tell him the whole time how you're now going to pool ALONE because he doesn't know how to behave and then tell him for days how awesome it was (maybe choose one with super fancy waterslides and stuff and take pictures). Passive/aggresive punishment?

My daughter responds to having her internet and tv privileges taken away now that she is a little older. She hasnt needed to be spanked since she was about 3, and even then it was only needed a few times (safety issues like running right into the street without looking). She hasn't done anything really bad, but if she did I will use the "work horse" punishment: make her mow our 6 acres with the push mower vs john deer riding mower, weed the garden, organize the storage room....etc

If the son was that young OP should have been watching him intensely. Anything could happen. Even something as simple as the kid running in excitement, slipping and landing in the pool.