Where is an after masthead light positioned on a vessel?

The after masthead light is positioned at least 4.5 metres higher than the forward light to ensure proper visibility and identification of the vessel's orientation and direction when viewed from another vessel. This height difference is crucial for distinguishing the type of vessel and its heading, especially at night or in reduced visibility conditions.

By positioning the after masthead light higher, it becomes more apparent to other vessels that are approaching from behind or at angles, allowing them to assess the movement and course of the vessel more effectively. The regulations governing vessel navigation aim to minimize the risk of collisions by ensuring clear delineation of vessel types and their navigation status.

While there are regulations surrounding the positioning of lights, such as a sternlight, the after masthead light must be higher than the forward light to maintain a clear visual hierarchy and assist in safe navigation.