Chart Navigation & Plotting · Plotting Conventions — Fix vs DR vs EP
On the plot, a position symbol of a square denotes:
- AA danger bearing
- BA fix
- CA dead-reckoning position
- DAn estimated position (EP)✓ Correct
Explanation
A square marks an estimated position (a DR adjusted for current/leeway). A fix is a small circle (or ringed dot), and a dead-reckoning position is a semicircle. Each carries the time, so the type and reliability of a position are read at a glance.
Authority: Bowditch (Pub. No. 9), Plotting Symbols
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