what do 2 short blasts mean?

Altering course to port, turning to port, you've got wind....

The question we need to answer, before we can answer the question you are asking is: "what does the question mean?"
 
All wrong.

In Pwllheli harbour, it means (as demonstrated for me this year)

Woohoo, hey over here, yes I am waving at you as I pass your pontoon, look at us, we're on our way out.

I should have followed with the rest of the horn pattern, after the waving gap he gave a medium single toot to say goodbye to his pal on the pontoon.

made me laugh any way.
 
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