I doubt the ships are apprised of the actual situation

So you think they're being lied to? Why would the port authority leave a bunch of ships sitting off port when they can just send them away?? Makes no sense.

I don't think a captain can just choose to turn around back to home port.

Well, if I was a ship captain, I'd put in a call to headquarters, tell them I'm not being allowed into port, and ask for instructions. I'd also mention that "just sitting here" is not an option.

But that's just me...