How should you respond to a vessel that is showing both a red and green light?

When a vessel is showing both a red and green light, it indicates that it is approaching you head-on. The red light is visible on the port (left) side of the vessel, while the green light is visible on the starboard (right) side. According to navigation rules, when you see both lights, it means you are approaching a situation where you may need to maintain your course and speed, because both vessels are on a collision course.

In this scenario, maintaining your course is necessary to avoid confusion about the right of way. The situation demands prudent navigation to ensure safety, and neither vessel should alter course without a clear understanding of the other’s intentions. The other options do not consider the appropriate navigational rules designed to prevent collisions when two vessels are on a direct path towards each other.