How can you identify the side of a dredge pipeline at night?

Identifying the side of a dredge pipeline at night is crucial for navigational safety, and observing two red lights is a reliable method for doing so. In maritime navigation, red lights are commonly used as a signal for certain types of equipment, including dredge operations, indicating they are present in that vicinity. The use of two red lights helps mariners distinguish the exact location and orientation of the pipeline, providing important information for safe passage.

While other options may involve navigational aids or signals, they do not specifically pertain to identifying the dredge pipeline at night. Radar is a tool used for detecting the presence of objects, but it wouldn't provide information about the specific side of the pipeline. A warning siren would alert nearby vessels to a potential hazard, but it doesn't assist in visually identifying the dredge itself. Flashing green lights typically indicate something different in maritime signaling and would not be associated with the dredge pipeline's position. Therefore, the observation of two red lights is the clear and correct method for identifying the side of a dredge pipeline during nighttime navigation.