(nautical, historical) Any early device for measuring the speed of a moving ship, where a sailor threw a floating object overboard and used a sandglass to measure the time it took to pass between two points on deck.

plural of log jam

A logan: a rocking or balanced stone.

plural of logging rock

plural of log chip

(nautical) A double slate, marked and ruled on the inside, for recording the log.

(nautical) The board, in the form of a quadrant, attached to a logline.

plural of log-glass

plural of log reel

(nautical) A reel on which the logline is wound.