Water quality status and bacteria risk rating
📍 North Shore Oʻahu — Summer snorkeling · Longboard surf break
Chunʻs Reef is a beloved North Shore spot with excellent water quality during calm summer months. The open ocean circulation and rocky coastline mean minimal sediment and very low bacteria from runoff. Like all North Shore spots, the primary danger is not water quality but seasonal surf — not bacteria.
Based on: Open ocean flushing, no significant stream input, rocky substrate, remote North Shore location
The Department of Health recommends at least 72 hours after heavy rain before swimming. Even remote North Shore beaches can receive runoff during heavy Oahu rainstorms.
Free alerts when water quality changes at your beach.
⚠️ 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 DOH Clean Water Branch before entering the water.
When in doubt, donʻt go out. 🤙