🔍 Key Concepts

• Converting per standard magnetic compass (psc) bearings to true bearings using variation and deviation from the compass correction table on the plotting sheet or exam reference • Plotting three lines of position (LOPs) from known lights to obtain a three-bearing fix • Comparing the plotted fix with the answer-choice positions by checking latitude/longitude grid lines carefully

💭 Think About

• How do you convert a bearing given per standard magnetic compass into a true bearing before plotting on the chart? Think about the order of applying deviation and variation. • Once you’ve converted your bearings, in what direction do you plot them from each light—do you draw the line from the light toward your vessel or from your vessel toward the light? • After plotting, how can you quickly decide which multiple-choice position best matches your fix without redoing all of the math?

✅ Before You Answer

• Make sure you are using the correct compass correction (deviation and variation) values for that area and heading from the exam’s standard tables or the plotting sheet. • Confirm that each bearing is plotted as a reciprocal (from the light to the ship) line of position on the chart, not from the ship to the light. • Verify that the latitude and longitude of your fix match one of the choices within a few tenths of a minute, and that the fix lies in a realistic spot relative to Point Judith, Block Island North Point, and Watch Hill.