Almost everyone who visits New Zealand and travels North and South Island has this dilemma: Do I have to book the Cook Strait ferry…
It all depends on when you are travelling and if you have a very tight schedule or not. In December and January, it is a good idea to book with one of the two companies: Bluebridge or InterIslander, Especially when you prefer an early morning sail. Down site, when your trip is taking longer than planned, you need to hurry to be in time. Both companies do offer a Flexi Ticket, so you can change your crossing to another date or time (depending availability)
Want to more about Cook Strait: Wikipedia Cook Strait
Cook Strait ferry crossing: a little holiday on its own…