lubber's mark vs lubber's point

lubber's mark and lubber's point both are nouns.

Word	Noun	Adjective	Verb	Adverb
lubber's mark	Yes	No	No	No
lubber's point	Yes	No	No	No

As nouns, lubber's mark and lubber's point are synonyms defined as:

lubber's mark and lubber's point: a fixed line on a ship's compass indicating its heading

Other synonyms of lubber's mark include lubber's line, lubber line.

lubber's mark (noun)	lubber's point (noun)
a fixed line on a ship's compass indicating its heading	a fixed line on a ship's compass indicating its heading