On a scarlet ellipse 2 1/2 inches (6.35 cm) by 2 1/8 inches (5.40 cm) with long axis vertical within a 3/16 inch (.48 cm) yellow border a black silhouette of Diamond Head surmounted by a gold projectile 1 11/16 inches (4.29 cm) long and 5/8 inch (1.59 cm) wide.
The oval and projectile are the distinguishing features of the Coast Artillery insignia. Diamond Head is distinctive of Oahu, the most important island of the Hawaiian group, and is the location of the first American fortification in Hawaii, and the most prominent landmark of Hawaii seen by visitors from the mainland.
The shoulder sleeve insignia was approved on 8 May 1936. (TIOH Dwg. No. A-1-265)