What to know before you go
Occasional surge from south swells entering the bay, slightly reduced visibility
Calm, excellent snorkeling, warm water, but crowded conditions can lead to fin injuries
| Lifeguards | Yes |
| Nearest Hospital | Kaiser Moanalua (10 mi) |
| Cell Coverage | Good |
| Emergency | Call 911 — Ocean Safety: (808) 723-8170 |
Weak swimmers should avoid the outer reef areas where the keyhole channel creates a current pulling toward open ocean. Reef shoes recommended for everyone.
After heavy rain, bacteria and pollutants from runoff contaminate coastal waters. Wait at least 72 hours after heavy rain and until the water clears before entering. This applies to Hanauma Bay and every beach in Hawaiʻi.
Coral cuts from shallow reef. Strong current in keyhole channel. Overcrowding during peak hours. Requires reservation.
Yes. Nearest hospital: Kaiser Moanalua (10 mi). Cell phone coverage: Good.
Winter: Occasional surge from south swells entering the bay, slightly reduced visibility. Summer: Calm, excellent snorkeling, warm water, but crowded conditions can lead to fin injuries
Weak swimmers should avoid the outer reef areas where the keyhole channel creates a current pulling toward open ocean. Reef shoes recommended for everyone.
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⚠️ Important Disclaimer
Safe to Swim Hawaii is an independent passion project — it is not affiliated with the Hawaii Department of Health, any entity mentioned on this page, or any government agency or hotel brand. Water quality ratings on this site are estimates based on publicly available testing data and geographic analysis. They are not real-time measurements and may not reflect current conditions.
Always verify current water quality conditions with the Hawaii Department of Health Clean Water Branch before entering the water. This site is for informational purposes only and should not be the sole basis for any swimming decisions.
When in doubt, donʻt go out. 🤙