You are underway on course 137°T at a speed of 16.2 knots. You sight a rock bearing 134°T at a radar range of 4.6 miles at 1508. If you change course at 1514, what is the course to steer to leave the rock abeam to port at 1.5 miles?

Correct Answer: Option A — 162°T

After 6 minutes at 16.2 knots, the vessel has traveled 1.62 miles. Plotting the initial position and the desired CPA of 1.5 miles to port requires a course change. Solving the relative motion triangle for the new heading results in 162°T to safely clear the rock.