Hanauma Bay

The bay is a breached tuff cone flooded by the sea, and the sheltered reef inside made it one of the most popular snorkelling sites in the world - which nearly killed it. By the 1990s around three million visitors a year were standing on coral, feeding fish and degrading the water, and fish behaviour and reef health had visibly changed. The response has been progressively stricter: a mandatory nine-minute conservation video before entry, an entry fee for non-residents, a daily cap, advance reservations that release on a schedule and go within minutes, and closure two days a week - Mondays and Tuesdays - to let the bay rest. Reef fish numbers and coral condition have improved measurably since.

What you'll find

• A flooded volcanic crater - with a sheltered reef inside.
• A mandatory conservation video - before anyone enters.
• A daily cap and advance reservations - released on a schedule.
• Two closed days a week - to let the reef recover.

When to go

Year round; closed Mondays and Tuesdays. Half a day.

What to expect

Reservations release at a set time and are gone within minutes - without one there is no entry. The walk back up from the beach is steep. Standing on coral and feeding fish are prohibited. Reef sunscreen rules apply.

Nearby

Koko Head is above; Honolulu is west.

Key facts