Warning signs, evacuation steps, and what every beach visitor must know
Don't pack up, don't take photos, don't wait for confirmation. Leave everything and move away from the coast.
Go to ground at least 100 feet in elevation or 1 mile inland from the coast. Follow blue tsunami evacuation route signs.
If you can't reach high ground, go to the highest floor of a sturdy, reinforced concrete building (4+ stories). This is a last resort.
Do NOT return to the coast until civil defense authorities give an official all-clear. Tsunami events often involve multiple waves — the first may not be the largest.
A tsunami can arrive before any official warning. These natural signs mean evacuate immediately:
If shaking is intense enough to make standing difficult, or lasts more than 20 seconds, move to high ground immediately
If the ocean suddenly pulls back, exposing the sea floor — this is a major warning. The wave is coming. Run immediately.
A loud roaring like a train or jet engine from the ocean direction — evacuate immediately
Guided ocean tours include trained crew who know evacuation routes and safety protocols.
Tours listed via Viator and GetYourGuide. Safe to Swim Hawaii may earn a commission if you book, at no extra cost to you.
The 72-hour rule is the standard guideline from the Hawaii Department of Health: avoid swimming for at least 72 hours after heavy rain stops, especially near stream mouths, canal outlets, and areas with brown or discolored water. This applies to all beaches across all islands.
Bacteria from urban runoff, agricultural land, and aging cesspool systems enters the ocean through streams and storm drains. Hawaii has approximately 88,000 cesspools — more than any other state — many of which leak untreated sewage into groundwater that eventually reaches the coast. Beaches near known cesspool contamination areas carry higher risk, particularly after rainfall.
This guide is for general informational purposes only. For official tsunami warnings and emergency guidance, always follow Hawaii Emergency Management Agency (HI-EMA) and local civil defense instructions. Safe to Swim Hawaii is not affiliated with any government emergency agency.
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. 🤙
Free alerts when advisories change at your beach.
Safe to Swim Hawaii aggregates water quality data from six independent sources to provide broader coverage than any single agency. Our sources include the Hawaii Department of Health Clean Water Branch (beach advisories and bacteria testing), USGS National Water Information System (25 stream monitoring stations across all islands), NOAA CO-OPS (tide levels and water temperature), NDBC (wave buoys and ocean conditions), NWS Honolulu (weather and marine alerts), and City & County of Honolulu Environmental Services (Kailua Bay water testing and spill reports).
Historical bacteria risk ratings on this site are based on DOH testing data, Surfrider Foundation monitoring, geographic analysis (stream proximity, cesspool contamination areas, coastal development), and advisory frequency. These are historical assessments, not live measurements. Always check the live advisory status at the top of each page and verify conditions with the Hawaii DOH Clean Water Branch before entering the water.
⚠️ Important Disclaimer
Safe to Swim Hawaii is an independent passion project — not affiliated with the Hawaii Department of Health or any government agency. Water quality ratings 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 DOH Clean Water Branch before entering the water.
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. 🤙