What is meant by an 'alternate system of navigation lights'?

An 'alternate system of navigation lights' refers to a backup system that includes masthead lights, sidelights, a sternlight, and anchor lights. This definition aligns with the requirements set forth in the COLREGs (International Regulations for Preventing Collisions at Sea), which establish standards for nautical lighting to ensure safe navigation at night and in reduced visibility.

The need for an alternate system arises from the recognition that vessels must maintain visibility and communicate their presence and intentions to others on the water. A complete set of navigation lights is crucial for delineating the position and orientation of a vessel, enabling other mariners to ascertain the size, type, and direction of movement. Should the primary lighting system fail, having a duly equipped alternate system ensures that safety is not compromised.

This is distinct from just sidelights and anchor lights, as all essential components of a complete lighting set are necessary for a fully functional alternate system. Furthermore, while a primary system of colored lights might reference the basic navigation lights used when the vessel is underway, it does not pertain to the concept of an alternate navigation system designed for backup. A simplified version of nautical signaling does not encapsulate the requirement for a comprehensive backup lighting system. Thus, selecting the definition highlighting a complete backup