Final answer:
When encountering a lateral red marker while boating, keep it on your starboard side or port side depending on your direction of travel to maintain a safe passage. Following navigation rules and the buoyage system is important for safe boating.
Step-by-step explanation:
When you encounter a lateral red marker, also known as a buoy with a bell, while boating, you should keep it on your starboard (right) side as you pass it. This indicates that you are in the correct channel. By keeping the red marker on your starboard side, you can avoid running aground or hitting any underwater obstructions.
If you encounter a lateral red marker as you are returning to the mainland from the sea, you should now keep it on your port (left) side to maintain a safe passage.
Remember to always follow navigation rules and pay attention to the buoyage system to ensure safe boating!