The Big Island's Kona coast has some of Hawaii's warmest, clearest water. Here's what you need to know about water quality at the top snorkel spots — from Two Step to manta ray dives.
The Big Island's Kona and Kohala (west) coasts are frequently cited as having some of the clearest, cleanest ocean water in all of Hawaii. The lava coastline has minimal freshwater runoff compared to other islands, and the warm, calm, leeward conditions mean excellent visibility most of the year. The Kona coast also benefits from being far from major population centers.
The Hilo (east) side is a different story — it's one of the wettest areas in the country and runoff regularly affects water quality near shore. See our Big Island beach guide for the full picture.
The Big Island's most beloved shore snorkeling spot. Named for the two-step lava shelf entry into the ocean next to Puʻuhonua o Hōnaunau (Place of Refuge) National Historical Park. Consistently exceptional water quality — no freshwater runoff, strong ocean circulation, and a protected bay that keeps conditions calm most days. Expect turtles, spinner dolphins, rays, and outstanding reef fish diversity. The entry isn't sandy but is manageable with fins. Arrive early to beat tour groups.
Hawaii's most celebrated snorkel site. A state marine life conservation district with jaw-dropping visibility, spinner dolphins, and pristine coral. The Captain Cook Monument on the north shore is only accessible by kayak or tour boat from Napoʻopoʻo Beach. Water quality is consistently excellent — this is a protected area with strict regulations limiting boat and visitor numbers. See our Kealakekua area guide. Book a boat tour or rent a kayak for the best access.
One of the most beautiful beaches on the Kona coast — bright white sand, impossibly clear turquoise water, and calm conditions most of the year. Excellent snorkeling along the rocky edges of the bay. Water quality is consistently very good here due to the open ocean exposure and lava coastline. Very limited parking (fills by 8am on weekends) but worth the early arrival. See our Kua Bay guide.
The closest reliable reef snorkeling to downtown Kailua-Kona. Shallow, protected bay with a large resident turtle population. Easy entry from the beach. The bay can get murky after rain due to its proximity to runoff sources. Check our Kahalūʻu Beach water quality page for current conditions. Historically has generally good water quality but is more susceptible to runoff than outer Kona coast spots.
One of the most spectacular wildlife experiences anywhere in the world. Giant Pacific manta rays (up to 12-foot wingspan) gather at Garden Eel Cove and Manta Village most nights to feed on plankton attracted by lights. Most tours depart from Keauhou Bay. The offshore water quality is consistently excellent. The mantas are harmless filter feeders. One of the Big Island's absolute must-do experiences.
The best snorkeling on the Hilo side, with a black lava shelf hosting diverse reef fish and frequent turtle sightings. A unique experience given the black sand beach. However, Hilo gets enormous rainfall and water quality can degrade significantly after storms. Always check conditions visually — if the water looks brown or murky near the park, avoid entering. See our Richardson Beach water quality guide.
The Big Island's two sides are night and day for water quality. The Kona coast (west) is dry, sunny, and has minimal runoff — it's Hawaii's most consistently clear snorkeling water. The Hilo coast (east) is wet, receives massive rainfall, and water quality near shore can be significantly impacted after rain. Apply the standard 72-hour rule after heavy rain on the Hilo side. On the Kona side, the rule still applies near stream mouths, but open reef spots like Two Step are rarely affected.
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⚠️ Important Disclaimer
Safe to Swim Hawaii is an independent passion project — not affiliated with any government agency. Water quality assessments are estimates based on publicly available data. Tour links are affiliate links — we may earn a commission at no extra cost to you.
Always verify current conditions with the Hawaii DOH Clean Water Branch before entering the water.
When in doubt, don't go out.