Blue Maomao Arch
Depth is the range from the top of the site to its usual maximum; "recommended cert" is the mainstream-agency level operators usually ask for, not a legal rule. Currents and visibility change daily — treat everything here as planning ranges.
The arch does one thing and does it perfectly: blue maomao school inside in such numbers that the passage becomes a moving wall of silver-blue, parting around divers and sealing behind them. Light pours in from both ends, the boulder floor bounces it upward, and for a few minutes everyone in the group is inside a bait ball that has no predator. Around the edges, kelp and jeweled encrusting life carry the usual Poor Knights payload of nudibranchs, and demoiselles shoal where the arch opens to the sea. It is shallow, brief, and among the most photographed moments in New Zealand diving.
The moment you come for: Wall-to-wall blue maomao, cathedral light through the arch, easy depth
Topography: Rock archway and boulder floor connecting two open faces of the reef
Current: Surge through the archway on swell days is the only real variable.
Know before you splash
Hazards: Surge in the archway when swell runs; time the swim between sets.
Conservation: Full no-take marine reserve; the schools are this dense because nothing here is fished.
Who you'll meet
For photographers
Wide angle: ★★★★★ · Macro: ★★★☆☆ — editors' 1–5 rating of what this site gives each style of shooting