Should you fly or take the ferry between the North and South Islands?
The ferry can be part of the journey, but it is not always the smartest move. Fly when time is tight or the route does not naturally use Wellington and Picton; ferry when the crossing actually supports the trip.
Answer
The ferry has romance: a real crossing, changing light, the sense of leaving one island and arriving on another. It also has logistics: terminals, weather, vehicle bookings, timing and the risk that the crossing controls too much of a short itinerary. Flying can feel less romantic but may protect a route that wants Auckland or Rotorua on one side and Queenstown or Christchurch on the other. The ferry works best when Wellington, Picton, Marlborough or the upper South Island already belong in the plan. It works less well when you are bending the whole trip just to avoid an internal flight.
Recheck before you go
Transport schedules can change. Check current timings before you book around them.