🔍 Key Concepts

• Relative position of the buoy at 1022 (bearing and range) versus your track line on 126°T • How to construct or imagine a right triangle for a 0.5 NM abeam distance (port side) from the buoy • Effect of course alteration at 1026 on where your new track will pass relative to the buoy

💭 Think About

• First, sketch your original course (126°T) and plot the buoy’s position from your ship at 1022. Is the buoy ahead of you, off your bow, or abaft your beam? • From the buoy’s fixed position, what line must your new course follow so that your closest point of approach (CPA) is 0.5 NM on your port beam? Think of a line tangent to a 0.5 NM circle around the buoy. • How does the 4-minute delay (from 1022 to 1026) affect your own ship’s position before you alter course, and how does that shift the geometry of your final course line past the buoy?

✅ Before You Answer

• Compute the distance traveled in 4 minutes at 14.8 knots and advance your ship’s position before plotting the course change. • Make sure the buoy is plotted as a fixed point and that your new course line just touches (is tangent to) a 0.5 NM radius circle drawn around the buoy on the port side. • Check that the chosen answer gives a course that passes the buoy on the port side, not starboard, and that the perpendicular distance from the track line to the buoy is 0.5 NM.