Black Sand Beach — Water quality & snorkeling conditions
📍 Makena, South Maui — Hidden gem near Big Beach
Oneuli Beach (ʻOneʻuli means "dark sand" in Hawaiian) sits within Makena State Park, backed by undeveloped lava fields that limit agricultural and urban runoff. The open south-facing shoreline receives good ocean flushing from the Maui channel.
Water clarity is typically excellent, especially along the rocky lava outcroppings that frame the beach. These rocky areas support thriving coral colonies and diverse marine life including Hawaiian green sea turtles (hōnu), which frequently rest on the black sand.
Based on: Undeveloped watershed, good ocean circulation, rocky volcanic substrate
Stay out of the ocean for at least 72 hours after heavy rain. Makena's lava landscape drains quickly and Oneuli typically recovers well, but visible brown or murky water is always a signal to wait.
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⚠️ Important Disclaimer
Safe to Swim Hawaii is an independent passion project — not affiliated with the Hawaii Department of Health. Ratings are estimates based on publicly available data and are not real-time measurements.
Always verify with the Hawaii Department of Health Clean Water Branch before swimming.
When in doubt, don't go out. 🤙