Mr Rinaldo's Bath

Mr Rinaldo enjoyed having a bath more than anything else he did. He lived in a large Victorian building, where the plumbing wasn't up to very much, full of draughts this time of the year coming through the sash windows and creaking floorboards, and the bath itself was a huge one on rusted claw feet of a larger-than-life mutancy of appearance, and he found it difficult to climb into and even more difficult to climb out of that bath. He often cringed at the brown running lines of yellow or brown that made its once white innards more like the skin of a diseased zebra than anything else.
The hot tap croaked upon turning but did allow in a good flow of scaldingly hot water at a generous, if stuttering, pace. Naturally, he had to ensure that his later turning on of the cold tap worked equally well as the hot one - otherwise he would become nothing better than a boiled lobster, if that's not too hackneyed a phrase to use. The trouble was that the cold tap was not very dependable and often gave up the ghost even before it had croaked. Then, he would be left with a good hour or so sitting on the edge of the bath in his stringy dressing-gown to allow the water to cool to a level hot enough but not too hot. But once in, he was in.
He loved his ducks, he loved the soap he collected in all manner of carved shapes, that would now be blurred by the lathering Mr Rinaldo loved smarming himself all over with. He loved his scrubbing brush, too, now a bit worse for wear, its bristles having become more like the bottom of a newly dredged quarry. But it did set his skin tingling and his teeth on edge simply to look at it and anticipate its first contact with his skin.
The water swished and swilled around him as he luxuriously allowed its warmth to take away any memory of the chill in the air. There was one mystery however that he had never solved. However much he loved creating waves with the gentle pumping up and down of his knees, the waves were never satisfying enough. But he knew a wave would not be a wave at all if it was strong enough to spill water over the edge of the bath. That would be a self-defeating wave. A wave to be a satisfying wave needed to be strong enough to lift up the loose bits of his body but not too strong so as to drain the bath of water. Tonight it was cooling anyway, and he would soon be forced to struggle out, torso turned and knees down to assist leverage.
No, the actual mystery was of a wave that occurred in his bathwater without him causing it. Often he would relax, sprawled out as far as he could, only the barest amount of face left above the water like a nosy island, resisting the onset of the bathroom's chill that the water was now absorbing, and he remained still for at least five minutes, stock still, until he felt the mysterious wave swirl gently over and above him till it splashed across the face with a cheeky slap. He never knew how that wave had generated itself. He often joked that the bath on its outlandish claw feet was actually a living creature itself. But that didn't hold water.