You are underway on course 215°T at 12 knots. The current is 000°T at 2.3 knots. What is the speed being made good?

Correct Answer: Option A — 10.2 knots

Vector addition using the Law of Cosines or a maneuvering board determines the resultant vector. The vessel's velocity vector (215°T, 12 knots) and current vector (000°T, 2.3 knots) combine to produce a speed made good of 10.2 knots, calculated by resolving components along the track line.