sea lane; ocean route; deep-sea route
Refers to a shipping route across the open ocean, typically for long-distance maritime transport.
This ocean route connects Asia and Europe.
航路 is a general term for a sea route or shipping lane, while 遠洋航路 specifically refers to a deep-sea or ocean-going route.
Compound of 遠洋 (えんよう, 'deep sea, ocean') and 航路 (こうろ, 'sea route, shipping lane').