Jaguars eat caymans. Many youtube videos demonstrate. Not all kitties dislike the water.
There is a real good video of a jaguar leaping off an embankment into water that was way over it’s head. You can see him struggling with something under the water. You can finally see the Cayman when the jaguar surfaces with it in his mouth. I definitely thought the Cayman had the advantage in deep water but that jaguar proved me wrong.