trade route vs ship route

trade route and ship route both are nouns.

Word	Noun	Adjective	Verb	Adverb
trade route	Yes	No	No	No
ship route	Yes	No	No	No

As nouns, trade route and ship route are synonyms defined as:

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

Other synonyms of trade route include sea lane, seaway.

trade route (noun)	ship route (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
a route followed by traders (usually in caravans)