October 11, 2020

Introduction to sailings

‘Sailings’ is a term given to various methods used to determine courses and distances to be steamed when travelling from one geographical position to another. There are six different “sailings”, ie Parallel, Plane, Middle Latitude, Mercator, Great Circle and a combination of Great Circle and one of the others. During […]
October 5, 2020

Parallel sailing

By parallel sailing we mean travelling along a parallel of latitude from one place to another. This means that one would either be travelling directly westward or eastward [270° (T) or 090° (T)]. The distance along a parallel of latitude between two particular meridians decreases as the meridians converge towards […]
August 28, 2020

Plane sailing

When we refer to plane sailing we mean sailing from one position to another where the latitude and longitude of each is different to the other.  Because we are using a mean latitude, this method is not very accurate over long distances and should be confined to distances of 600 […]
October 15, 2020

Mercator sailings

Scale of a Mercator chart. Because the equator is shown on a Mercator chart as a straight line of definite length and the meridians appear as straight lines perpendicular to it, the longitude scale is fixed by that length and is constant in all latitudes. The latitude scale, on the […]