Actually, they don't hate water if they are introduced to it while they are young. My parents had a siamese when I was a baby, and somehow (I wasn't very observant as I was a little young at the time ) taught it to swim. Whenever they were in the lake, it would (cat)paddle around the dock with them. They have picture of me and the cat taking a bath in one of those old metal washtubs. The cat is right in there with me, playing with the rubber duck. I had a look on my face along the lines of "Who the heck invited him?"
You are one of the few lucky (?) ones, my previous cat was born in my house, but water was always a big no no (a watergun made a great 'teaching' tool lol). The thought of a swimming cat is pretty funny, I have heard of it before, but never seen it.