Blue Hole

Kosrae's Blue Hole is a vertical shaft that drops from 5 meters at the surface through a narrow chimney before opening into a dramatic cavern at 30 meters, with a sheer outer wall continuing well beyond recreational limits. Shafts of sunlight pierce the entrance at midday, illuminating clouds of glassy sweepers and silversides that pack the chimney walls. The outer drop-off beyond the hole's rim hosts grey reef sharks cruising the thermocline and large Napoleon wrasse patrolling the coral-encrusted lip.