What to know before you go
Trade winds can be stronger, occasional wrap-around north swells
Generally calm with consistent trade winds, popular for kayaking and windsurfing
| Lifeguards | Yes |
| Nearest Hospital | Adventist Health Castle (3 mi) |
| Cell Coverage | Good |
| Emergency | Call 911 — Ocean Safety: (808) 723-8170 |
Kayakers should not paddle beyond Popoia Island. Swimmers should avoid the north end near the marsh outfall, especially after rain. Watch for Portuguese man-o-war 8-10 days after the full moon.
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 Kailua Beach and every beach in Hawaiʻi.
Kawainui Marsh bacteria drainage at north end. Man-o-war jellyfish seasonally. Windy conditions — lost kayakers. Strong current near Popoia Island.
Yes. Nearest hospital: Adventist Health Castle (3 mi). Cell phone coverage: Good.
Winter: Trade winds can be stronger, occasional wrap-around north swells. Summer: Generally calm with consistent trade winds, popular for kayaking and windsurfing
Kayakers should not paddle beyond Popoia Island. Swimmers should avoid the north end near the marsh outfall, especially after rain. Watch for Portuguese man-o-war 8-10 days after the full moon.
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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. 🤙