I also had a tomcat that also loved water. Actually an older brother of this one. He used to sit in bathtub and jump on the faucet in attempt to make water run
that was a brillent cat! Too bad we can’t have sent him to. Congress. He would have more common sense!
When I was a teen, friends a few houses over had a cat who liked to swim in our lake. You could call to the cat and it would swim out to you in a boat.
I had a big black feral cat that would loved water also. Only drank from running water - would duck his head under the water, then turn his head sideways and lap water. Would try to catch water drops with his paw. Would play in the sprinkler while I was watering my garden. I had a friend who called this cat “a black Tennessee wethead”. If he didn’t come when I called, I’d turn on the hose and splash a bit. That would always bring him running. You could entertain him for hours with running water!
My current big boy is a tuxedo and he will get in the shower with me - sit in the shower seat and bat at the water with his paws and lick the water off my skin. He also wants to drink from moving water - will splash and make a mess - hence our current fountain watering arrangements.
I think liking water is a learned behavior - if the adult cat will play in the water, the kittens will also.