What is the length of a flag measured from the staff to the outside edge referred to as?

The length of a flag measured from the staff to the outside edge is referred to as the "fly." This term specifically describes the portion of the flag that extends horizontally away from the staff when the flag is flown. The fly is an important aspect of flag design and specification, as it defines the appearance and size when the flag is displayed. Understanding the terminology associated with flags is crucial for proper flag handling and display, particularly for boatswain's mates who are responsible for the care and use of flags in maritime operations.

In contrast, "hoist" refers to the vertical measurement of the flag from the bottom edge to the top of the staff. "Staff length" denotes the total length of the flagpole itself, while "flag width" is a less commonly used term that may cause confusion, as it typically does not directly correspond to an established part of flag terminology. Thus, recognizing "fly" as the correct term ensures clarity in maritime practice and communication.