An object which serves as an indication of direction or position; a landmark or seamark. Frequently figurative.

A conspicuous object distinguishable at sea which serves to guide or warn sailors in navigation.

An object in the landscape, which, by its conspicuousness, serves as a guide in the direction of one's course (originally and esp. as a guide to…

a navigational aid for sailors and pilots, which is distinctively marked to maximize its visibility in daylight.

one of ‘those objects which, kept in line or in transit, guide the pilot while working into port, as trees, spires, buoys, etc.’ (Adm. Smyth 1867).

The mark left or reached by the tide at high or (rarely) low water; by extension, the mark left by a river flood. Also, a post or the like set up to…

a buoy or other mark set to indicate a shoal.

North American. Nautical. = range marker, n. 3.

North American. Nautical. Each of two or more markers used as a navigational aid, appearing in alignment to shipping which is following a safe…

a buoy or other seamark representing one of the cardinal points of the compass, used to indicate the safe direction of travel (in relation to the…