Which statement about the reciprocal marks on your compass bezel is true?

Which statement about the reciprocal marks on your compass bezel is true?

• A. Are required by law.
• B. Are set at 90 degrees from the index marks.
• C. Help you to find your way back to your starting point without having to surface to take a new heading.
• D. Are set in line with the lubber line.

Answer: (C)

The idea being tested is how a compass bezel helps you return to your starting point under water. Reciprocal marks provide the return bearing. When you swim to a point and set a course, you can use the mark opposite that bearing to guide you back. By aligning the bezel so that the reciprocal mark points in the opposite direction of your outbound heading, you establish the direction you must swim to return to your entry point. This lets you follow a straight path back without needing to surface to take a new bearing. It’s not about legal requirements, it isn’t about a 90-degree offset, and it isn’t tied to the lubber line—the useful thing is that the reciprocal mark gives you a quick, reliable return direction.

The idea being tested is how a compass bezel helps you return to your starting point under water. Reciprocal marks provide the return bearing. When you swim to a point and set a course, you can use the mark opposite that bearing to guide you back. By aligning the bezel so that the reciprocal mark points in the opposite direction of your outbound heading, you establish the direction you must swim to return to your entry point. This lets you follow a straight path back without needing to surface to take a new bearing. It’s not about legal requirements, it isn’t about a 90-degree offset, and it isn’t tied to the lubber line—the useful thing is that the reciprocal mark gives you a quick, reliable return direction.