You never know. Some breeds of cats, and some individual cats, tolerate or even like the water. I believe Tigers swim, to cross water or to hunt game in the water. Jaguars hunt crocodile-like animals, with their jaws capable of 700 pounds of pressure. I had an Abyssinian tabby who, though he didn't swim, would not shelter in the rain, but would do his hunting and roving and come back and let me towel him off. He had a sturdy undercoat, though short-haired, and was not demoralized by being wet in the least. It was like he'd had a nice swim. Most cats hunker down under a car, porch, shed, or bush and wait out rain, but you never know. Savannah may be warming up for a nice swim in that aquarium.