Hi and welcome to the forum
Yeh there is the fantasy booze cruise which is real good and you have a choice of two beach parties - Bedrock or Dirrty - only difference between two is the type of music u like. Waterpark is on the outskirts of napa and is truly a great day out. I always say the pub crawls are a waste of time - tag on and follow them if you must - but such a rip off - you will meet loads of people anyhow so why pay someone to show you the square.
Hope you enjoy - Di