How is longitude expressed in standard navigational practice?

Longitude in standard navigational practice is typically expressed in three digits to ensure precision and accuracy when defining positions on the Earth's surface. The expression of longitude in three digits allows for the representation of degrees within the range of 0 to 180 degrees east or west of the Prime Meridian.

When using terrestrial navigation, especially on charts or in electronic navigation systems, a three-digit format ensures that navigators can easily read and interpret the coordinates. For example, a longitude of 075 degrees would be expressed as "075" to maintain uniformity and facilitate communication among mariners and aviation professionals.

Expressing longitude in two digits would not provide enough detail for accurate positioning, especially in situations where precise navigation is critical, such as in narrow channels or near obstacles. Four-digit representation is generally reserved for further subdivisions of degrees into minutes and seconds, which is not the usual format for standard longitude expression. Hence, the practice of using three digits is widely accepted and essential for navigation purposes.