I've sailed on Lake Erie, in a 36 foot sail boat. I've been to boat shows where it costs nothing to go in. I have great experience in power boats, even so much that my dad asks me to dock his. I've been to many expos, for boats, cars, hunting/fishing..........I've never had to pay to get in. I guess things have changed.
All the shows I have been to, or looked at, have always had a ticket price. Usually you can get discounts.
I sailed in SF years ago on a 45footer. That was a fast day.