As I write this, I am sat in the Kaitaki Plus lounge, observing the drinking habits of those around me. I know a number of the people drinking are driving because I saw them in the queues waiting to board.
One couple, for example, has consumed 4 glasses of wine and 4 beers so far. It's free in the lounge too.
Now, I know you could argue that it's like a pub. Except it isn't. Here, no one is getting a taxi home if they drove a vehicle onto the ship.
Seems to me time drivers were not served alcohol on board. There's not even a mention of drink driving etc.