The Coromandel is home to spectacular underwater seascapes, popular for snorkelling and diving.
Just off the fine golden sands of the famous Cathedral Cove lies the Te-Whanganui-aHei Marine Reserve, where the calm waters of the Mercury Bay harbour teeming wildlife, sponge gardens and reefs. Gemstone Bay has a snorkel trail, where even a novice can experience the marine magic using the buoys with information panels and images for fish identification.
Situated off the coast of the Mercury Bay, the 7 Mercury Islands offer some of the most varied underwater terrain in New Zealand. With submerged caves, pinnacles and drop-offs, the islands shelter a diverse range of species including crayfish, kingfish and moray eels. Popular with hunters and photographers as well as divers. Warm currents provide an ever-changing parade of whales, stingray and marlin and sub-tropical fish and turtles.
To the south east lie the Aldermen Islands, 12 nautical miles off the coast of Tairua. Here the volcanic origins of the region are evident by the vertical spines that soar from the sea floor, eroded remains of lava from a catastrophic eruption. These spines rise like organ pipes from the sandy bottom, providing rich feeding stations for sea life. Some pinnacles barely pierce the surface, so local knowledge is essential for navigating these waters. The underwater caverns, gullies and tunnels are majestic, world-class dive sites. The islands themselves are a wildlife sanctuary, home to several species of endangered reptiles which can be seen sunning themselves on the sheer rocks, alongside vivid nudibranch. The Aldermen encompass 134 hectares, providing a vast underwater playground filled with wild beauty.