seaward side; side facing the sea
Refers to the side of something (a building, road, train seat, etc.) that is closer to or faces the sea. Often contrasted with 山側 (mountain side).
The seaward-side rooms in this hotel have a good view.
If you sit on the seaward side of the train, you can see the coastline.
Formed from 海 “sea” and 側 “side,” with sequential voicing changing かわ to がわ.