Formerly used on Lake Mead between 1935 and 1960.
After the completion of the Hoover Dam, the waters of Lake Mead rose rapidly, obscuring natural hazards beneath the newly formed lake. Although early explorers had mapped the topography of the area prior to the construction of the dam, fluctuating water levels, submerged rocks, and jagged canyon walls made night time navigation a challenge. Kerosene lanterns were used for nighttime travel on Lake Mead and the Colorado River to detect hazards and to signal other boats. These versatile navigational aids could be hung from the front of the boat, placed on a flat surface, or held by hand.