The way I read Mako's posts sounds like the booze is just flowing all the time. Maybe this depends on the group of people on board in any given week. If people express (or the crew senses) that people want to drink, maybe the alcohol comes out a bit more. During my week on the Pirate's Lady in August, there wasn't much mention of alcohol at all, other than mentioning that if you wanted some, it was there and about bar nights (we had an extra one because of bad weather). I only noticed a couple of people drinking at night but most went to their bunks fairly early anyway, and rum punch was only put out one night that I was aware of.
My perception of the crew was that they explained the rules (depth, drinking, etc) and expected you to follow them, but they weren't policing anything. There was a fair amount of "I went to 130', wink wink nudge nudge". (One guy showed me his computer after a dive, max depth was 213') They expected people to be responsible for themselves, so there was no computer checking or drink smelling, but they definitely did not come across as a bunch of drunken sailors either.