Milford Sound is miles from anywhere. You have to access by coach as the roads are (very) hairy and sometimes inaccessible by car. When we went in April, the road had been shut due to snow the day before and only reopened to coaches the next day. You can board the coach at Te Anau and then it is a 2 hour drive. The company also had coaches from Wellington but that was a 6 hour drive to Te Anau and then a further 2. We used the company Real Journeys. They were fine, provided an adequate packed lunch on the boat, and on that day it wasn’t full. I wouldn’t use them again, they specialise in large coachloads of tourists and it was sometimes difficult to find space to take decent photographs. However, that said, we thoroughly enjoyed our trip.
As you board the boat, you go straight into the downstairs level with windows all along and tables where you can eat lunch. Then there are stairs up to the open viewing platform which runs the length of the boat and affords superb views. Free tea and coffee is a nice bonus.
This is a full day trip and there are smaller companies operating there too, with smaller boats. Next time, we would consider using one of these. Next time, though, we would do Doubtful Sound and compare the two!