12 Things Every Visitor Should Know
Never turn your back on the ocean. Rogue waves can surge much farther up the beach than expected. Also, never swim alone at unguarded beaches, always check conditions before entering, and respect the 72-hour rain rule for water quality.
Hawaii averages 40-60 ocean drownings per year, with many victims being visitors unfamiliar with local conditions. Tourists account for a disproportionate share of drownings compared to residents.
Portuguese man-o-war (box jellyfish arrive on predictable cycles), sea urchins on rocky shores, and occasionally sharks. Jellyfish arrivals can be predicted using the lunar calendar. Always shuffle your feet when entering to avoid stepping on hidden marine life.
The Hawaii Department of Health recommends staying out of the ocean for at least 72 hours after heavy rain, even if the water looks clear. Bacteria and pollutants from runoff can linger in the water longer than the brown color does.
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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. “No DOH Alerts” means no advisory is currently posted — it does not mean the water was tested and found safe. DOH only monitors a fraction of Hawaii’s beaches, and some areas have no regular testing at all.
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.
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This site does not recommend or advise anyone to swim at any beach. We share government data and geographic analysis so you can make your own informed decisions. By using this site you accept full responsibility for your own safety. See our Terms of Use for full details.
When in doubt, don’t go out. 🤙