We flew from Christchurch to Auckland, and then the next day travelled north to the Bay of Islands. At the very top of NZ there are 71 islands that make up the 'bay of islands'. We had a whole afternoon when we got there so from Pahia (where we were staying) we got a ferry across to Russell, and had a walk over there. It seemed like a really nice place, and we walked to a view point, and there were some bars and restaurants over there.
The next day we went on a sailing trip, that we booked through the kiwi experience bus. We ended up just being us 3 plus one other person on the trip (plus the skipper) which made it really good. We got a chance to do a bit of sailing (mainly left it up to the poor guy who was on the trip with us). We stopped off at a beach, where we did some kayaking, and actually got in the sea! First time in New Zealand! Lunch was provided and it was one of the best sandwiches that I've eaten, whilst we were chilling on the beach the guy was making them on the boat. Then over lunch the skipper was telling us loads of random hilarious stories! On the way home it got sooo windy! And we were in gale force winds trying to get back to the harbour. I don't know if people don't normally book this activity for bay of islands on the kiwi experience but if you are thinking about this as a potential activity, then I would say do it!
Before we headed back to Auckland, in the morning we did a bit of a hike. There were a number of walking trails, but we went on a relatively short one, but it was quite uphill, but the view was good.