As redacted pointed out, the tugboats only take care of it out of port.
In motion it's on its own.
That said, I'm 99% this was a coordinated event.
And if so, it's HIGHLY sophisticated.
The timing was flawless, execution flawless.
In that way, it reminds me of the Russian mobilization in Syria the U.S. state dept. was quietly surprised by years back when "wiping out terrorists".