Your vessel will sail from a position in LAT 8°51.0'N, LONG 81°31.0'W to a position at LAT 33°51.5'S, LONG 151°13.0'E. The distance by great circle is 7,635 miles, and you estimate an average speed of 15.0 knots. What is your estimated zone time of arrival if you depart at 1510 ZT, on 23 July?

Correct Answer: Option B — 1110, 14 August

Divide the great circle distance (7,635 miles) by the SOA (15.0 knots) to find total elapsed time of 509 hours (21 days, 5 hours). Adding this steaming time plus zone description adjustments to the departure date of 23 July yields an estimated zone time of arrival of 1110 on 14 August.