The great sea battles of the First World war and prior were fought using visually-aimed weapons limited to the distance a ship could see. Some increase in distance was achieved by mounting spotters on the tops of tall masts, but it was not until ships were paired with aircraft that the range of targetting was feasible over the horizon.

This brought its own problems, however, particularly when ships operated in groups. How was a spotter to know which ship was his amidst the crowd in the distance? To help the observers separate the ships at a distance, the US Navy began painting the tops of their turrets in bright colors to distinguish one ship from another. While there was some effort in the 1920s, most of the wide spread marking systems did not reach the fleet until the 1930s.

The below documents are presented to help the reader understand this system and how it might affect the appearance of a particular ship. It is an incomplete set of records, but more will be added as they are located in the National Archives.

Documents:
• Fleet Organization, 2nd Quarter, FY 1941 - Fleet organization, order of ships within squadrons, & colors.
• 1939-24L - Effective from August 6th, 1938 until June of 1940.
• US Fleet Letter 1, March, 1941 Effective from March 24, 1941 through the attack on Pearl Harbor.
• Battleship Turret Top Color Chart - Based on US Fleet Letter 1, above.