🔍 Key Concepts
• Course made good is the true direction between two positions over the ground—not necessarily the 195°T heading steered.
• Start from the 2045 position in step 6, 37°13.50′N, 075°38.05′W, and independently construct the 2111 position from step 7 using Buoy “14” abeam to starboard.
• Correct step 7’s plotting assumption: do not force the 2111 position onto a 195°T line from the 2045 fix. Retain its approximately 6.4 nautical miles and 14.8 knots only after checking the independently plotted endpoint.
💭 Think About
• With the vessel heading 195°T, what true bearing places Buoy “14” 90° to starboard? What reciprocal direction must you plot from the buoy toward the vessel?
• Mark the vessel 0.9 nautical mile from Buoy “14” along that reciprocal direction. What true direction does the line from the step 6 position to this independently plotted 2111 position show?
• Does the distance between these two positions still round to approximately 6.4 nautical miles, supporting step 7’s speed made good over 26 minutes?
✅ Before You Answer
• Plot the endpoint from the buoy, using the reciprocal of its starboard-abeam bearing; do not confuse the buoy’s bearing from the vessel with the vessel’s bearing from the buoy.
• Remeasure the endpoint-to-endpoint distance on the chart’s latitude scale. Check step 7 using Time=26min×60min1h, then Speed=Time in hoursDistance in nautical miles.
• Read the course from 2045 toward 2111, referenced to true north. These are true directions, so no variation or gyro-error correction is needed.