Which publication is cited for finding great circle distances between ports?

The correct publication for finding great circle distances between ports is "Distances Between Ports." This publication provides essential navigational data that includes the distances between various ports, calculated based on great circle routes. Great circle sailing is a technique used in navigation that helps vessels plot the shortest course over the earth's surface, which is essential for efficient travel times and fuel conservation.

Using this publication allows navigators to quickly reference and determine the most direct routes between two locations, enhancing planning and operational efficacy. The distances are typically presented in nautical miles and are calculated using established geodetic principles, making it an authoritative source for this specific navigational requirement.

In contrast, Fleet Guides offer a variety of information about various ports, including harbor details and services, while Pilot Charts provide extensive information on oceanographic conditions such as currents and winds across different seasons. The Light List contains information primarily about navigation aids, such as lighthouses, buoys, and beacons, focusing on their characteristics and positioning rather than distance calculations. Therefore, when needing to determine great circle distances specifically, "Distances Between Ports" is the definitive reference.