On 5 May your 1600 zone time DR position is LAT 17°28' S, LONG 143°39' E. You are on course 316°T at a speed of 17 knots. You observed 3 celestial bodies. Determine the latitude and longitude of your 1800 running fix.

Correct Answer: Option B — LAT 17°05.2'S, LONG 143°11.4'E

Applying course and speed over the elapsed time interval advances morning or evening sights into a reliable running fix. Calculations utilize standard dead reckoning vector projection methods.