6th cruise, all with Carnival Corp brands; first one on Princess. We are North Americans who chose this far-from-home trip for the itinerary: 3 ports on New Zealand's South Island; 3 ports on the North Island, one day of scenic cruising in Fiordland's National Park. We were told that we might have "bad weather" on this cruise; we took that to mean we should pack rain gear. No one mentioned possible port cancellations.
Very high winds first forced the cancellation of the Fiordlands cruising and the port of Dunedin. Ship diverted to Wellington (not on the original itinerary), where the staff did a great job of offering last-minute shore excursions on a Saturday. We were mildly disappointed, but we had a beautiful day in Wellington.
At the end of the day, we got back on the ship and were told that the next port, Akaroa, also was cancelled and we would stay in Wellington a second day. We had explored the major attractions near the ship, and no shore excursions were being offered on the second day (a Sunday). We didn't know what to do in Wellington, so we asked the two people at the passenger services desk if shops and the town tourist office were open. They looked at each other and said they didn't know. "Some probably are, and some probably aren't," was the answer. They did not offer to make phone calls to find out.
We spent a week in Sydney prior to the cruise, and left for the airport when the cruise returned to Sydney. Lots to do right where the ship docks.
This was the port with the most expensive shore excursions. Most were bundled with one appealing activity; and one or two that didn't appeal. (As North Americans, we have visited Yellowstone and have seen thermal pools and geysers, for example.) So instead, we went to Tauranga and toured the Elms Mission House (admission cost $5) and walked around the base of Mt. Maunganui, the large green hill near where the ship docks. Cost: free. The path is well marked and fairly level, and the scenery is spectacular.