lubber's line

or lubber line

noun Navigation.

a vertical line on the forward inner side of the bowl of a fixed compass, used as a reference mark indicating the heading of a vessel.

Origin of lubber's line

First recorded in 1855–65
Also called lubber's mark, lubber's point. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

British Dictionary definitions for lubber line

lubber line


a mark on a ship's compass that designates the fore-and-aft axis of the vesselAlso called: lubber's line
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012