dead reckoning

plural dead reckonings · alternative ded reckoning · alternative DR

1. countableuncountablenavigationA method of estimating the position of a ship or aircraft by applying estimates of the distance and direction travelled from a previously known position. In respect to ships/boats, it excludes the effect of wind and current on the vessel.

   In a certain sense the captains were good sailors, but their knowledge and ambition were limited to dead reckoning, the tar bucket and marlinspike, a wife in every port, and plenty of rum and tobacco with no desire or ability to master the higher branches of navigation and seamanship.

   1911, Arthur Hamilton Clark, The Clipper Ship Era 1843-1869, Chapter 2

   1 more example

   Earlier, airmail pilots relied almost entirely on visual navigation and dead reckoning, a method that sounds simple in theory, but required remarkable concentration and experience. A pilot would plot a route on a map, take a compass heading, estimate his airspeed, and calculate how long it should take to reach the next landmark.

   2026 March 7, Sthitapragta Chakraborty, “America Once Built Giant Arrows to Guide Pilots Across the Country, and Some Still Exist Today”, in Skip Boring, archived from the original on 24 Jul 2026