Modifications of Sailings

Abstract

Methods of calculating the course and the distance between two points by knowing the latitudes and longitudes of them on the earth, or calculating the latitude and the longitude of the arrival point by the course and the distance from the known departure point, are called sailings. And in terms of sailings, middle latitude sailing and Mercator sailing have been employed. Here if the former method is classified, they will be mean middle latitude sailing and true middle latitude sailing, and they are based on plane sailing and parallel sailing. In the previous paper, the author pointed out the problems and described the counterplan concerning plane sailing and parallel sailing. In this paper, he attempts to point out the problems of Mercator sailing and the contradiction of the so-called true middle latitude sailing. In conclusion, he attempts to compare those sailings and consider the results of a concrete example, and recommends the modified Mercator sailing (tentatively named).