Yes, I realise that most people aren't going to want to schedule something during session times (regardless of whether or not they actually attend any sessions). Which was why I hesitated about suggesting the cruise in the first place as I suspected it would get turned into A Meetup. And it's not like there can't be two or even three groups that get together for a boat cruise.
Regardless of what other people do, I'm going either Saturday or Sunday morning (probably Saturday). If other people want to come along then, that's cool and if not I'll go alone. There are plenty of other meet-ups and I don't feel the need to be surgically attached to the herd of fandom the entire time I'm in Chicago anyway.