Picture the coastline as one long line: sea on one side, land on the other. `Onshore` always points at the land side of that line. Sometimes the line is a real beach — an onshore well, an onshore wind, a storm coming onshore. Sometimes the line is the edge of your own country, and then keeping work or money onshore means keeping it at home. Whichever line it is, the word puts you on the land side of it.
可以把海岸線想成一條長長的線。一邊是海，一邊是陸地。onshore 講的永遠是「陸地那一邊」。有時候那條線是真的沙灘：陸上的油井、吹上岸的風、登陸的颱風。有時候那條線是自己國家的邊界：把錢和工作留在線內，就是 onshore。不管是哪條線，這個字都把你放在陸地那一側。
From the word’s history
The Wiktionary entry in this packet records the word simply as on + shore.
本批資料的 Wiktionary 條目只寫了一句：onshore 來自 on 加 shore。這正好就是它的核心畫面——「在岸上／朝岸上」。
Wiktionary entry supplied in evidence packet (kaikki:3f6f69a190036ae4:1328891746): `From on + shore.`
登入就可以看每一支怎麼連回核心畫面。