The original ironwork of the watch room and lantern at Diamond Head are still in use. The present tower, built in 1917, was constructed of reinforced concrete and stands 55 feet high. The original lighting equipment consisted of a 3rd order Fresnel lens and a special multiple-wick kerosene oil lamp, imported from France in 1899. These pieces of equipment were standard throughout the world for lights of this size and importance.

The first step in modernization at Diamond Head Lighthouse was to replace the fixed or steady light with the present day flashing light. Diamond Head Lighthouse has been progressively improved until today it stands as a modern automated USCG aid to navigation.

The commercially-powered light is backed up by a battery-powered light equipped to switch on in case of power outage. An electronic sensing device also monitors the main light and activates the backup light in case of any type of failure. The clocks automatically turn on the equipment at sunset and turn it off at sunrise. A photoelectric cell alarm control system was formerly installed, which caused a bell to ring in the base of the tower and also in the nearby dwelling when the light failed. The system was removed during the war years.

Built 147 feet above sea level, Diamond Head Light can be seen as far away as 18 miles and has an intensity of 60,000 candlepower. The light shows a red sector to warn vessels away from the reefs off Waikiki Beach . The large dwelling at Diamond Head Light was occupied by the superintendent of the 19th Lighthouse District prior to the merger of the Lighthouse Service with the Coast Guard in 1939. Operating under the U.S. Department of Commerce, the 19th District included the Hawaiian Islands, Midway Island, Guam and American Samoa.

From 1939 to 1945, this dwelling, together with a small dwelling constructed during this time, served as the 14th Coast Guard District Radio Station. In 1946, the radio station was moved to its present site in Wahiawa, Hawai`i. The large building at the light station was renovated and has been the residence of the 14th Coast Guard District commander since that time. (more on USCG Dist 14)

Diamond Head Lighthouse was placed on the National Register of Historic Places in 1980.

Lighthouses are often thought of as towers of mystique and romantic charm, isolated at the foot of storm-tossed waves beating upon the rocky shore. Though the days of the traditional lighthouse keepers are gone, the duty of the lighthouse continues. And like the hundreds of sentinels of the shore, Diamond Head Light stands its watch guiding the weary mariner safely passed its rocky shore.