I love water no matter what form it comes in. I'll get wet in the rain on purpose because I like the feel of cool water seeping through my clothes (another part of it is that I can't stand umbrellas). My favorite part of visiting a sporting complex is taking endless turns to go to the swimming pool and swim back and forth until I get cold, then to the sauna, then back to the swimming pool again. As a child, I used to spend hours on end in the lake or in the sea, which made my parents worried as they kept thinking I might catch a serious cold, and I'll still bathe this long if I'm given a chance. It's difficult to say what is it exactly that I love so much about water - I like the feel of it against my skin, its softness and coolness, the melodic splashing sounds it will make, the light sparkling on its surface. Besides, it makes me feel very serene when I come out (as far as I know it's that way for most people, not just me).
I've never paid attention to the bathtub vortex thing, but it might be interesting to watch. What I do know is that sitting in a jacuzzi that's lit by underwater lamps is a fascinating experience (and if there's sunlight falling onto the surface, it's twice as fascinating). All those eruptions of dancing golden and silver sparks. It's like watching fireworks happening underwater.