What does a red sidelights indicate on a vessel?

Red sidelights on a vessel indicate the port side. In maritime navigation, vessels are required to display specific lights to help indicate their position and orientation to other boats, particularly during nighttime or low visibility conditions. The use of colored lights helps in identifying different aspects of the vessel's layout.

Port sidelights are always red to help other vessels determine the direction the vessel is heading. When another boat observes a red light, it understands that it is seeing the vessel's left side (port side). This is important for navigation, collision avoidance, and for understanding the relative position of vessels in relation to one another.

The white light at the bow represents the front of the vessel, while the stern light, typically white, indicates the back of the vessel. The starboard side, represented by a green light, indicates the right side of the vessel. Understanding the color coding of navigation lights is essential for safe boating practices.