The MLCD extends from the groin at the end of Kapahulu Avenue to the ewa (west) wall of the Natatorium, from the highwater mark seaward a distance of 500 yards or to the edge of the fringing reef, whichever is greater. A reef flat extends out from the Waikiki Aquarium seawall a distance of about 35 yards to a dredged channel, then continues on the other side of the channel. Most fish in this area are found along the channel's shoreline side (which has a number of small caves), along the Natatorium wall, and near the exposed parts of the reef on the channel's seaward side. The channel itself is about 8 feet deep, and depths above the reef flat are generally less than 3 to 4 feet.

Known as Leahi in Hawaiian, named Diamond Head in the 19th century by the British who thought they discovered diamonds in the crator. They were calcite crystals that were worthless. Diamond Head was formed over a 100,000 years ago. Diamond Head was used as a strategic military lookout in the early 1900's. Diamond Head was named a National Natural Landmark in 1968. Diamond Head is a hiking destination with excellent views of Waikiki and the Pacific Ocean.