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?

Question

Your vessel will sail from a position in LAT 8&deg;51.0'N, LONG 81&deg;31.0'W to a position at LAT 33&deg;51.5'S, LONG 151&deg;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?

Accepted Answer

Option A: 1110, 14 August. Calculate total travel time by dividing distance by speed (7635/15 = 509 hours). Convert 509 hours to 21 days and 5 hours. Applying the time zone difference between the departure and arrival longitudes, the elapsed time added to the departure date results in an arrival on 14 August at 1110.