Ah... that explains why people use sand. No one I know has used sand, probably because we all live in places where you couldn't leave a wavemaster outside in the winter anyway - and I've never had one crack. When I first got one for my class, there was a hose connection down the hall, but sand would have to have been brought in up a flight of stairs (no elevator) one sack at a time - which was a major consideration. Also, the room we were in at the time had carpet - carpet dries, but sand is a pain to get out of carpet pile. Now that we're in a room with a decent wood floor, I might consider changing the contents of the wavemaster... except that first we'd have to get it up the stairs to the nearest drain, and then haul the sand in through half the building (not too bad with a dolly) and then down a different flight of stairs, with a nice 180 turn in the middle of the staircase... but still, you bring up some good points about sand that I hadn't considered in that context.
