What is the purpose of showing shapes and lights on vessels?

The purpose of showing shapes and lights on vessels is to signal other vessels in navigational situations. This is crucial for safe maritime navigation, as these visual signals provide important information about a vessel's identity, status, and intentions. For instance, different lights and shapes indicate whether a vessel is at anchor, under way, fishing, restricted in ability to maneuver, or constrained by its draft. By displaying these signals, vessels can communicate critical information to other mariners, helping to prevent collisions and ensuring safe passage in busy waterways. This system of signals is standardized under the COLREGs to minimize confusion and enhance navigational safety on the water.