You are enroute to assist vessel A. Vessel A is underway at 5.5 knots on course 033°T, and bears 248°T at 64 miles from you. What is the time to intercept if you make 13 knots?

Correct Answer: Option D — 3h 44m

Solving a relative motion intercept problem requires constructing a current-triangle vector diagram. Using your speed of 13 knots and Vessel A's vector (5.5 knots on 033°T) starting from a bearing of 248°T at 64 miles yields an intercept duration of precisely 3 hours and 44 minutes.