Chart Navigation & Plotting · Set & Drift
A vessel steers 000° at 10 knots through the water. A current sets 090° at 2 knots. The vessel's actual track over the ground will be:
- ADue north at 10 knots
- BDue south at 8 knots
- CDue east at 2 knots
- DSlightly east of north at a bit over 10 knots✓ Correct
Explanation
Adding the 10-knot northward water vector and the 2-knot eastward current vector gives a resultant pointing slightly east of north with a speed of about √(10² + 2²) ≈ 10.2 knots. The vessel is pushed east of its heading.
Authority: Bowditch, Pub. No. 9 (current triangle)
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