Alderman Islands – Hauraki Gulf & Coromandel

Site Overview

The Alderman Islands are a remote group of offshore pinnacles in the outer Hauraki Gulf that offer some of the most pristine and exhilarating diving in the entire Auckland region. Located far from the mainland and urban influence, the islands support marine ecosystems that remain virtually untouched, with massive schools of kingfish numbering in the thousands, huge pink maomao aggregations, and seasonal bronze whaler shark encounters. Long-finned boarfish, a species rarely seen at more accessible sites, are regularly encountered at the deeper pinnacle slopes. The underwater topography consists of dramatic rocky pinnacles rising from deep water, creating concentrated marine habitats where nutrient-rich currents support extraordinary biodiversity. The soft coral coverage on the pinnacle walls is exceptional, with dense orange and purple colonies swaying in the current alongside black coral fans and colourful gorgonians. The exposed offshore location ensures crystal-clear water with visibility often exceeding 30 metres, making the Alderman Islands a premier wide-angle photography destination. The long boat crossing from Whitianga or Leigh adds to the expedition atmosphere and ensures that the islands receive very few divers, preserving the pristine conditions and unafraid marine life. The combination of remote wilderness, massive fish schools, and potential shark encounters makes the Alderman Islands the ultimate offshore diving experience in the Hauraki Gulf.