USCG Exam PracticeEstimated position from current set & drift
A vessel steers C 270 T at S 6 kts. A current sets 180 T at 3 kts. Which statement correctly describes the relationship between the DR position and the EP after one hour?
- ✓ The EP will be 3 nm south of the DR position, plotted as a dot inside a squareCorrect
- B. The EP will be 3 nm north of the DR position, plotted as a dot with a semicircle
- C. The EP will coincide with the DR position because current only affects course, not position
- D. The EP will be 3 nm west of the DR position, plotted as a dot inside a square
Why A is correct
Bowditch Ch. 8 §803 directs laying off the current's set and drift for elapsed time from the DR position. Set 180 T at 3 kts for one hour displaces the EP 3 nm in the direction of 180 T (south) from the DR position. The EP symbol is a dot inside a square (Bowditch Ch. 8 §802).