Take the trolley around town (free), walk to the outdoor Marketplace and the gardens around the art museum.
Next stop was Burnie. Not sure why it is not listed as an option on this site, but the trip to the Wild Animal Preserve is definitely worthwhile.
Also not on this list is Milford Sound. The optional overland excursion is pricey, but well worth the cost. It felt like we had been on a cruise, were now on an entirely different vacation, and then returned for another cruise! Don't miss this if you have the chance to take it.
The actual port is now Akaroa due to the earthquakes that occurred in Christchurch. Glad we went to Christchurch - the devastation is evident but the town is rebuilding and the gardens are absolutely spectacular.
Picton was next port. Wonderful dolphin and Ship Cove excursion.
Only 4 hours here. Enough time to walk to the museum and also take a gondola up the hill for the view and the botanic gardens. As this was the only overcast day we had, we went to the museum and then back to the ship (no view from the gondola due to fog).
Napier was next port. Wine tasting at 3 locations, very fun and educational. Also good for napping once we were back on the bus!
Next port was Tauranga. Take the hike up Mt. Maunganui. It's worth it for the views and the sheep on the hillside next to you!
Visited a home, treated like honored guests, watched sheep being herded and then got to shear one. It's much harder than it looks! Back to airport on the bus where our luggage was waiting. Nice way to end the cruise.