What is the Least Distance Track (LDT)?
The Least Distance Track (LDT) is the shortest geographical distance between two ports. In the open ocean this will approximate to a great circle track which is the shortest distance between 2 points on a globe. The LDT will appear curved on all graphics because it is constructed using the common Mercator projection favored by seafarers. The LDT is the distance given by most marine distance tables and therefore commonly utilized in voyage estimates. Although it is the shortest distance geographically between two points it is quite often NOT the most efficient route to proceed on passage.
