Captain's License / Study Guides
📐Chart Plotting
Chart Plotting is the #2 failure point after Rules of the Road. Only 10 questions, but you need 90% — that means you can only miss ONE. It's open book and hands-on: you work on an actual NOAA training chart with dividers and parallel rules.
What's Covered
Basic Course Plotting
Plotting courses between waypoints, measuring true course from the chart, converting to magnetic and compass courses.
TVMDC Conversions
Converting between True, Variation, Magnetic, Deviation, and Compass headings. Applying CAE (Correcting Add East).
Dead Reckoning (DR)
Plotting the DR track from course and speed, labeling positions with proper symbols (half-circle), time labels in 24-hour format.
Fix from Visual Bearings
Taking two or more visual bearings, plotting Lines of Position (LOP), identifying the fix at their intersection.
Running Fix
Advancing an earlier LOP to cross with a later LOP when only one landmark is visible. Critical technique for the exam.
Set & Drift
Determining the current's set (direction) and drift (speed) from the difference between DR position and actual fix.
Current Sailing
Calculating the course to steer to compensate for known current. Vector triangle method.
ETA & Speed-Time-Distance
Using 60 D ST (60 × Distance = Speed × Time) for all speed, time, and distance calculations.
Tide Calculations
Using the Rule of Twelfths to calculate tide height at a given time between high and low water.
Study Tips
- 1.Practice on the actual NOAA Training Chart 1210TR before your exam — it's the same chart used at the REC
- 2.Label everything: 3-digit course above the line with T or M, speed below the line, 4-digit time at each position
- 3.Use the latitude scale (sides of the chart) for distance, NEVER the longitude scale (top/bottom)
- 4.For TVMDC: write it as a column and fill in what you know, solve for the unknown
- 5.Running fix: advance the earlier LOP parallel to itself along the course line by the distance traveled
- 6.Buy FriXion erasable pens — you can erase mistakes cleanly on the training chart
Common Mistakes
- ✗Using the longitude scale instead of the latitude scale to measure distance
- ✗Reading the reciprocal bearing (180° off) from the compass rose
- ✗Applying variation in the wrong direction — if variation is 15°W, subtract when going True→Magnetic
- ✗Forgetting to label positions with proper symbols: circle = fix, half-circle = DR, square = EP
- ✗Not using 24-hour time format for position labels (use 1430, not 2:30 PM)
- ✗Measuring course from the wrong compass rose ring (outer = True, inner = Magnetic)
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