Chip log

For the ship's log, see Logbook.
Diagram of a chip log attached to a log-line and reel on a ship

A chip log, also called common log,[1] ship log, or just log, is a navigation tool mariners use to estimate the speed of a vessel through water. The word knot, to mean nautical mile per hour, derives from this measurement method.

  1. ^ Dixon, John Whitly (1911). "Log" . In Chisholm, Hugh (ed.). Encyclopædia Britannica. Vol. 16 (11th ed.). Cambridge University Press. p. 864.