It seems like there are 2 types of ski clubs being discussed here. One type where there is a club boat and another type where the members bring their own boat. I don't think these two types can be lumped together and run the same way. The club boat variety can sustain 30 members because there are not boat loads of families showing up. Members typically come alone for a set or two before work, at lunch or after work. As for the time slot thing, I don't see how on earth that could work. People would be late, no shows, wanting to switch etc. You'd spend more time trying to figure out the time slots than skiing! And what about the weather? Say you book a time slot and a lightening storm comes up just then, you don't get to ski that day. Weather conditions are hugely important in this sport and I don't see how one could work time slots around that.