HELP how to make my dog to stop barking when there is people in the pool??

Hey! I was wondering if anyone here can give me a help in a very annoying behavior of my beloved and otherwise perfect dog 🙂

His name is Koda, he is a border collie, 4yo.

He loves swimming, on the beach and in the pool. And he is a very calm border collie

His problem is: whenever he is outside of the pool, and someone is inside the pool, he barks a lot, and doesn’t stop until he jumps in the water. When he gets inside, he keeps “eating” the water and swimming.

It is noticeable that he is obsessed with the “little waves” that appear whenever the water is moving in the pool.

I know that it might be impossible to break his obsession with the pool water, but I was wondering if it might be possible to make him stop barking…

Does any of you have any experience with this?? How do I train him to prevent this?

I have already tried to calm him down whenever he is near the pool, training with treats, on a leash.

But no treat has greater value than the moving water 😅. If only he stopped barking, it would be great!