ship route vs sea lane

ship route and sea lane both are nouns.

Word	Noun	Adjective	Verb	Adverb
ship route	Yes	No	No	No
sea lane	Yes	No	No	No

As nouns, ship route and sea lane are synonyms defined as:

ship route and sea lane: a lane at sea that is a regularly used route for vessels

Other synonyms of ship route include seaway, trade route.

ship route (noun)	sea lane (noun)
a lane at sea that is a regularly used route for vessels	a lane at sea that is a regularly used route for vessels