Kauaʻi — Poipu & the South Shore

Diving on Kauaʻi means the south shore: about 95% of it happens off this coast, which is the better protected side for most of the year. The shops sit in Kōloa and Poʻipū, and dive boats leave daily from Poʻipū and Port Allen; the shorter trips are two dives at sites along the south shore, some with groups of six or fewer. Every shop also runs guided shore dives at Koloa Landing, a protected entry with calm water that doubles as the twilight and night dive. From May to September some boats add a three-tank crossing to Niʻihau, a separate trip rather than part of the south-shore day.

The reef is lava rock cut into ledges, caverns and arches. Sheraton Caverns, about 400 yards (370 m) off the Sheraton Kauai, is a popular boat site: three partial lava tubes with archways and overhangs, where sea turtles are everywhere and frogfish and black coral live. Turtle Bluffs is a small hill ringed by 15 to 20 ledges on three sides, a large arch dominates the site off the Beach House restaurant, and at Brennekes Ledge the reef drops off at around 18 m (60 ft) into an overhang. Triggerfish, surgeonfish, parrotfish, butterflyfish, frogfish, scorpionfish and moray eels fill the reefs, and the endangered Hawaiian green sea turtle appears on nearly every dive.

The coast has dives for beginners as well as experienced divers. Three Fingers is shallow with very little current, and Koloa Landing's calm, protected water suits divers new to the sport; the caution there is high south surf, anything over about 1.2 m (4 ft). Currents elsewhere change by the day, and at Brennekes Ledge, near the point at the east end of the south-side sites, the water can go from flat calm to a ripping torrent. Commercial diving at Tunnels is paused under current state rules.