Hi Mike,
There are no specific rules, (that I know of), about hosting a cbrat get-together (CBGT). Patti and I have hosted the Friday Harbor gathering for five years and have found it fun, rewarding. and surprisingly little work. Brats generally arrive from Friday noonish on, stay Friday and Saturday nights and depart sometime Sunday morning. Just what goes on in between varies from gathering to gathering. At Friday Harbor we have arranged a regular Friday evening dinner with a local restaurant, they give us a special menu because we have 50-60 people and it makes it easier for them to plan. Not everybody comes and no one worries. I try to give the restaurant a forecast, again, to help them plan. On Saturday people go their own ways, some fish/crab/shrimp, other see the sights in town or hang around the docks to chat, steal boat ideas, and enjoy each other's company. Saturday afternoon we have a true potluck dinner, people bring whatever they choose. Sometimes we have brat entertainment, sometimes not, sometimes we have a giveaway, sometimes not. The main needs are a place to put the food, (we rent some tables with costs defrayed by donations from earlier gatherings), room enough to sit, and sometimes a covered area. Sunday morning groups go to breakfast or sit around the dock and continue to chat (gossip) and everybody is usually gone by around noon. Beforehand I contact the marina, arrange space for an approximate number of expected boats, at Friday Harbor we are early in the season and have up to 40 boats so they are very glad to see us and give is a good price break. I contact the restaurant set a time and menu and at FH contact the local West Marine who kindly hosts us for coffee/donuts and gives a price break. We rent the tables, maybe print up a few handouts about local attractions and get ready to greet people. About the only moorage issues we have are trying to keep the brats together in one area, occasionally shooing other boats away, and handling lines for incoming boats. As far a choosing a location, we usually have some kind of a town fairly nearby but it is not a rule. The town provides restaurants, some shopping, maybe a little entertainment or resupplying. The real main attraction is the other brats and their boats. There have been successful gatherings with fewer than 10 boats. There have been rainy, windy and icy gatherings. Brats are just glad to see each other. Should you decide you are interested, Patti and I will be glad to offer any help we can.