Meaning of the word "at sea" in English

What does "at sea" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

at sea

US /æt siː/
UK /æt siː/

Idiom

1.

confused and not knowing what to do

Example:
After the sudden change in plans, I was completely at sea.
When it comes to advanced mathematics, I'm totally at sea.
2.

on a voyage on the sea

Example:
The sailors spent months at sea.
They were at sea for three weeks before reaching land.