at sea的二重义

at sea

• 表面意思

  on the ocean

  After three days at sea we sighted the land.

• 引申意思

  就好像行船之人误入了汪洋大海中的无风带，而四周又是一望无际的海平面。

• confused/have no ideas

  I’m totally at sea when assigned the task to reach the island.