The best tour of the trip so far, by a long way, was the day of sailing around the Bay of Islands on Te Kaihau. It was run by Tom, who owns the trimaran. The tour is brilliantly laid-back, stuffed with interesting things to do (snorkelling, helping set the sails, mussel fishing (collection? musselling?)) without feeling regimented in the least. Sitting/lying around on the deck was also fully acceptable, and we did a lot of that.
Out in the bay we had grandstand views of the gorgeous scenery and a few interesting historical spots, including Captain Cook’s first landing point in New Zealand (second-last photo) and the Waitangi Treaty Grounds (last photo), where New Zealand was founded as a country with the signing of an agreement between the Maori and the British Crown.