In 1911, a sixteen-foot-tall, skeletal tower was erected on the southwest rim of the crater where it had a focal plane of 173 feet above the water. The tower’s automated light, which went into service on March 11, 1911, was powered by acetylene and emitted a white flash every three seconds. The Lighthouse Service Bulletin noted that on March 18, 1921, Molokini Light, the first compressed acetylene gas light established in the Hawaiian Islands, completed ten years of service without having been extinguished.
In October 1925, Ralph Tinkham, superintendent of the Nineteenth Lighthouse District, dispatched the tender Kukui to replace the Molokini light tower. “The framework in the present tower,” Tinkham noted, “has deteriorated and we shall not only construct a new one, but shall also raise the height from 173 feet to 187 feet as complaints have been received from time to time that the light is hidden by a jutting piece of land to the north. The new light will raise it above this obstruction.”
Molokini Light burned for nineteen years and eight months without being extinguished. As the light flashed every three seconds, this amounted to approximately 207,000,000 flashes during this period. The lantern and flasher were exchanged for overhauling and cleaning about every four years. This impressive record of continuous service ended in November 1930, when either an air pocket or acetone in the gas line caused the light to go out.
This second light marked Molokini for twenty-two years until it too succumb to the elements and was replaced in 1947 by a twenty-five-foot skeletal tower, which displayed an electric light powered by batteries stored in a shack built inside the base of the tower. In April 1989, a powerful storm packing winds of over sixty miles an hour toppled the 1947 tower and sent it tumbling down the crater. Members of the Coast Guard ANT team were soon helicoptered to the island to erect a temporary beacon and later the metal pole and solar powered light that grace Molokini today.