Port official to hide teacher (13)

I believe the answer is:

harbourmaster

I'm a little stuck... Click here to teach me more about this clue!

'port official' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.

'hide teacher' is the wordplay.
'hide' becomes 'harbour' (harbouring is a kind of hiding).
'teacher' becomes 'master' (I've seen this before).
'harbour'+'master'='HARBOURMASTER'

'to' acts as a link.

Can you help me to learn more?

I've seen this clue in The Daily Express.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.