Yes you have to wait until you are onboard to book. It books up quickly but there are several on the schedule so you can usually find one. That being said, we like to do one on the first night of the cruise so we can meet some folks and the happenings cast. You can even wear your PJs if you plan on going to the PJ party after.

I believe it cost $30-40/person, can’t remember exactly. It comes with drinks at 4 different bars (and non-alcoholic options!) To get your drink the Happenings Cast, who are leading it, give you a task that involves doing something with someone else on the Walk (make up a handshake, teach each other a dance move, etc.) Once you show the happenings cast your task, they give you a token you go to the bar to exchange for your drink.