You’ve spent the last few days exploring the Coromandel Peninsula. Cathedral Cove, Karangahake Gorge, the Hauraki Rail Trail, and, of course, Hot Water Beach. But it feels like you’re missing something. The islands. You keep staring at them as you move from lookout points to the beaches to the scenic drives. You need to get out on the water.

The Mercury Islands lie five miles north of the Coromandel Peninsula. Red Mercury Island, plus five smaller islands, is an off-limits nature reserve that was established to protect more than 3,000 pairs of breeding Pycroft’s petrels. Great Mercury Island, to the west of the other islands, is the only inhabited island in the chain. The 5,000-acre island is the remains of a long-extinct volcano. It has white-sand beaches, hidden fishing holes, pristine scuba-diving spots, and panoramic views of the Pacific. But its two residences, which are available to rent, are luxurious and extremely expensive.

That doesn’t mean you can’t visit Great Mercury Island for the day. Windborne Charters offers a day trip that sails around the islands and anchors off the largest island. Board the 64-foot schooner early in the morning. It sails up the peninsula’s eastern coast, passing Hahei Beach—an actual pink-sand beach—and Opito Bay. The captain points out hidden spots and shares Māori legends along the way. Salt water sprays up the side of the boat. The wind whips through your now-knotted hair. While three dolphins race alongside the boat. As you head away from the shore, out into the open water, the islands look bigger and bigger. Red Mercury. Stanley. Atiu. Korapuki. Green. Then, finally, Great Mercury’s Huruhi Harbour.

The boat anchors in isolated Peachgrove Bay. As you take in your peaceful surroundings, a lunch of freshly caught tuna is served. When you finish, board a smaller boat to head to the shore. You have the whole afternoon to walk along the empty beach, go snorkeling to look for colorful fish, and search for geckos and tuataras on the rocks that line the beach. Your North Island trip finally feels complete.