Horseshoe Reef is a boat-accessed Oahu reef dive with crescent-shaped coral structure, a broad shallow-to-mid-depth profile, and a lively mix of fish, sharks, and turtles. It is a good fit for divers who want clear water, healthy coral, and enough structure to stay interesting without turning the dive into a hard current run. The site rewards relaxed reef cruising, careful buoyancy, and a little extra attention to surface traffic.