háng / hǎi / yuán / gēn / jù / jīng / wěi / xiàn / pàn / duàn / chuán / zhī / suǒ / zài / de / hǎi / yù航海员根据经纬线判断船只所在的海域。The navigator determines which sea area the ship is in based on the lines of latitude and longitude.