What does Rule 26 specify regarding anchor lights?

Rule 26 of the COLREGs pertains specifically to vessels at anchor and the requirements for displaying anchor lights. According to this rule, a vessel at anchor must exhibit a white light visible all around. This visibility is crucial to ensure that other vessels can identify the presence of an anchored vessel, especially in low visibility conditions or at night.

The requirement for a white light ensures a standardized means of signaling to other vessels that this particular vessel is stationary, which aids in preventing collisions. Since the light needs to be visible all around, it allows for safe navigation in the vicinity of the anchored vessel, alerting approaching vessels of its location regardless of their point of approach.

The other options do not align with the established COLREGs guidelines. For instance, the suggestion of a red light forward or a green light on the port side would not fulfill the requirement of indicating an anchored status, and not displaying any lights would increase the risk of collision, as it would not signal the vessel's presence effectively. Thus, the correct identification of the need for a white light aligns with the goals of navigation safety outlined in the regulations.