Maro Reef, Coral reef in Northwestern Hawaiian Islands, United States

Maro Reef is a coral reef system in the Northwestern Hawaiian Islands that spreads outward from its center in a wheel-like formation. The structure creates an expansive underwater landscape that shifts in appearance depending on tidal conditions.

American Captain Joseph Allen discovered this reef formation in 1820 while commanding a vessel named Maro across the Pacific Ocean. The reef took its name from the ship that first charted it, linking the place to early maritime exploration.

The reef carries the Hawaiian name Nalukākala and holds significance in the traditional navigation and fishing practices of Native Hawaiians. Visitors can sense this cultural connection to ancestral maritime knowledge, even though the place remains untouched by settlement.

Access to this protected reef requires special scientific permits and authorization due to its conservation status. The location is remote and sits far from shore, making it inaccessible to most casual visitors.

The reef harbors multiple species of stony and soft corals that have established themselves in this remote ecosystem. At high tide, much of the visible reef structure becomes submerged beneath the ocean surface.