Kewalo Pipe, Honolulu: diving the Oahu artificial reef

Kewalo Pipe, located approximately one mile off the Kewalo Basin Harbor near Waikiki, started its life as a storm drain pipeline. Over time, sections of this infrastructure have broken up and settled on the seabed, creating a fragmented yet cohesive artificial reef. You'll find these pipe sections encrusted with corals, lying amongst sandy patches and interspersed with naturally occurring finger reefs. This structure provides a textured environment where marine life can find shelter and foraging opportunities, making it a site with a well-defined underwater topography.

The dive profile here is relatively shallow, typically ranging from 11 to 20 metres. You'll descend onto this man-made structure, which extends across the sandy bottom. The scattered pipe sections form overhangs and crevices, offering numerous hiding spots for smaller creatures. As you navigate the site, you'll move between these broken pipe remnants, sand channels, and low-lying finger reefs, observing how the marine life adapts to both the artificial and natural structures. The straightforward depth profile allows for ample bottom time, giving you the opportunity to explore the various nooks and crannies.

This site is particularly active with benthic life. Keep an eye out for octopus, which you'll often find tucked away in the pipe sections or camouflaged against the surrounding reef. Moray eels also inhabit these crevices, occasionally peering out from their shelters. Frogfish, masters of camouflage, are present and require a keen eye to spot, often blending seamlessly with the corals and encrustations on the pipes. You'll find these sedentary species coexisting with more mobile inhabitants, adding to the site's rich biodiversity.

Beyond the pipes themselves, the surrounding reef environment attracts a variety of fish species. Schools of snapper and butterflyfish congregate around the structure, using it as a feeding ground and shelter. You may also encounter juvenile wrasses moving across the sand patches and among the smaller reef formations. Humuhumunukunukuapua'a, the Hawaiian state fish, are also commonly seen, adding colour to the reef scene. These species contribute to the overall vibrancy of the site, making each dive a visual experience.

The area is also known to host larger transient visitors. While not a daily occurrence, it is possible to encounter reef sharks, specifically white-tip reef sharks (Triaenodon obesus), cruising along the edges of the reef or resting under ledges. Green sea turtles (Chelonia mydas) are frequent visitors, often seen foraging on algae or resting on the bottom. The presence of these larger animals adds another dimension to the dive, creating moments of significant encounter without being the primary focus of the site.