The Kohala Coast — Hawaii's driest shore and home to its most spectacular white sand beaches
The Big Island's west coast — the Kohala and Kona coasts — sits in the rain shadow of Mauna Kea and Mauna Loa. Annual rainfall here is under 10 inches in most areas (compared to 200+ inches on the Hilo side). The result: white sand beaches with crystal-clear water, minimal runoff, and consistently Low Risk (1/5) water quality year-round. This is where most Big Island resort visitors stay — and for good reason.
Kaunaʻoa Beach (Mauna Kea Beach)
Pristine crescent of white sand near Mauna Kea Beach Hotel. Excellent swimming, good snorkeling at rocky edges. Public parking limited — arrive early.
Hapuna Beach
Consistently ranked one of America's best beaches. Wide, long, white sand. Lifeguard on duty. Body surfing. Facilities. First choice for most visitors.
Kua Bay (Maniniowali)
Spectacular turquoise water, top snorkeling at lava points. Sea turtles. Small lot — arrive by 9am. No food or rentals.
Anaehoʻomalu Bay (A-Bay)
Near Waikoloa Beach Resort. Calm, shallow bay. Sea turtles rest on beach. Good for beginner snorkelers. Watersports rentals available.
Kikaua Point Beach
Hidden gem near Kukiʻo area. Calm, protected. Requires knowledge of access road.
Kahaluʻu Beach Park
Kailua-Kona area. Best beginner snorkeling on the Big Island. Shallow reef, calm entry, sea turtles almost guaranteed. Lifeguard on duty.
South of Kailua-Kona, the coast becomes more rugged. The road narrows and the beaches are smaller and less developed — but the marine life is outstanding.
🦆 World's Best Manta Ray Experience
The Big Island's west coast is globally famous for its manta ray night snorkel and dive. Giant manta rays (wingspan up to 14 feet) gather near the Garden Eel Cove and Manta Village near the Kona airport to feed on plankton attracted by dive lights. This is consistently rated one of Hawaii's top wildlife encounters. Tours depart from Kailua-Kona nightly.
Top-rated experiences near this beach. Check water quality above, then plan your trip.
Tours listed via Viator and GetYourGuide. Safe to Swim Hawaii may earn a commission if you book, at no extra cost to you.
Free alerts when advisories change at your beach.
Hawaii’s Department of Health monitors approximately 57 beaches statewide through regular bacteria testing. However, with over 300 swimmable beaches across the islands, many popular spots have no regular testing program. Water quality varies significantly based on rainfall, stream proximity, coastal development, and ocean circulation patterns.
After heavy rain, streams and storm drains carry bacteria, sewage, pesticides, and sediment into coastal waters. The DOH recommends staying out of the ocean for at least 48 to 72 hours after heavy rain, even if the water appears clear. Brown or murky water is a visible sign of contamination, but bacteria can be present in clear water near stream mouths.
This site aggregates data from six sources — DOH advisories, USGS stream monitoring (25 stations), NOAA tide and temperature data, NDBC wave buoys, NWS weather alerts, and City & County of Honolulu water testing — to provide a more complete picture than any single source.
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.
Independent passion project — not affiliated with Hawaii DOH. Ratings not real-time. Verify with Hawaii DOH.
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. 🤙
⚠️ 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. 🤙