The flag of the Territory of Guam was adopted on February 9, 1948.
The territorial flag is dark blue with a narrow red border on all sides (border was a later addition). In the center of the flag is the coat of arms; an almond shaped emblem, which depicts a proa sailing in Agana Bay near Hagåtña, and GUAM coloured in red letters. The shape of the emblem recalls the slingshot stones used by the islanders’ ancestors. The landform at the back depicts the Punta Dos Amantes cliff on Guam. Charles Alan Pownall approved the flag’s shape in 1948.
As a compliment to the Guam flag and in response to Guam law providing for municipal flags, efforts were made to depict the culture of each Guam village. These efforts to design unique municipal flags were collaborated through the Mayors’ Council with the assistance of illustrative artist Gerard Aflague, a Guam born native. These flag designs reflect unique aspects of each of Guam’s municipal villages. Wikipedia