What is the correct formula to calculate the target angle?

• A. TB + TC + 180 = Target Angle
• B. TB - TC + 180 = Target Angle
• C. TB - TC - 180 = Target Angle
• D. TB + TC - 180 = Target Angle

Answer: (B)

The formula TB - TC + 180 = Target Angle is correct because it accurately accounts for the relationship between the base bearing (TB), the compass bearing (TC), and the necessary adjustment for a full rotation in navigation.

In this context, TB represents the target bearing, which is the direction toward which the vessel needs to steer. TC is the true course or bearing, which is the angle being measured relative to a reference point.

When determining the target angle, the objective is to find a course that incorporates the difference between the target bearing and the true course, then adjusts for the full 180-degree rotation. Adding 180 degrees effectively flips the angle to ensure that the target angle is correctly oriented within the relevant quadrant of a compass.

This approach is vital for navigation accuracy, especially when dealing with angles that may extend beyond the typical 0 to 180 degrees. The correct calculation ensures that the target angle points in the intended direction to maintain situational awareness and optimize course planning.