What feature must the letters for registration numbers possess?

The registration numbers on a boat are essential for identification, and they follow specific formatting requirements to ensure that they are easily readable and recognizable on the water. The correct answer emphasizes that these numbers must be separated by spaces or hyphens, which serves a crucial purpose.

When registration numbers are properly spaced or separated, it helps to enhance visibility and clarity. This is particularly important in busy environments where quick identification is necessary, such as during enforcement stops by coast guard officers or when reporting a lost or stolen vessel.

Additionally, when someone sees the registration number from a distance, having spaces or hyphens aids in quickly distinguishing the individual characters, making it easier for others to read and understand the full registration number, thus promoting safety and compliance with boating regulations.