Chaikou
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.
Chaikou faces north, so when summer winds go soft the zone turns into a bright, easy garden: dense thickets of branching and table corals in genuinely good health, hawksbills picking at sponges, porcupinefish loitering under ledges, and clouds of damsels and butterflyfish over every head. The boardwalk crossing the reef flat spares both diver and coral the usual shuffle, and the slope beyond stays gentle to twenty meters. It is the island's family-friendly face, better for unhurried second and third dives than for drama, and in clean Kuroshio water that is no complaint at all.
The moment you come for: Healthy branching-coral thickets, hawksbill encounters, easy boardwalk access
Topography: Reef flat and coral-garden slope with scattered heads on sand
Entry: A boardwalk over the reef flat on the north coast delivers snorkelers and divers past the surge zone; best in the southerly and calm seasons.
Know before you splash
Hazards: Exposed to the northeast monsoon; surge closes the zone in the windy season.
Conservation: Use the boardwalk and marked channels; the reef flat is shallow enough to damage on foot.
Who you'll meet
Clownfish & Anemonefish
Hawksbill Turtle
Nudibranchs
Porcupinefish
For photographers
Wide angle: ★★★★☆ · Macro: ★★★☆☆ — editors' 1–5 rating of what this site gives each style of shooting