Final answer:
When seeing a vessel's red and white lights off the starboard bow, it indicates that you're seeing its port side and should maneuver to avoid a collision, staying alert and ready to change course or speed if necessary.
Step-by-step explanation:
If you see another vessel's red and white lights off your starboard bow, it indicates that you are seeing the port side of that vessel and it has the right of way. According to the navigation rules, you should maneuver to avoid a collision. This generally means you should maintain your course and speed if the red light is not accompanied by a green light, but stay alert and be prepared to slow down or take evasive action if it becomes necessary to avoid a close-quarters situation.