That isn't really an issue due to the South China Sea which the navy can use. A ship in port in vulnerable anyways so isn't a position the navy would want to be in if military support is required. The navy will want distance until the area is secure from Chinese naval, land and air assets have been dealt with. At best it remove a symbol of support, nothing more.
The legislation the U.S. signed is supposed to just be a 'symbol of support' and nothing more...correct? That is the way everyone here treats it. Yet these symbols of support mean something as the other side reacts to them. As you now see China doing.
And, not allowing U.S. navy ships is not the only thing that China did. She put sanctions on certain pro-democracy and pro-west groups. Such as "National Endowment for Democracy" and "Human Rights Watch and Freedom House".
Slowly shutting the doors. Slowly getting ready.
And of course, because America's bill which openly supports the protesters is just 'symbolic' then China doesn't have to worry about any other symbolic actions. Right?
Now you hear N. Korea rattling a sabre. They are demanding Trump end the U.S. hostile deneuclearzation policies. Do you think that is coincidence at this time? Just a symbolic gesture I'm sure....correct? The U.S. used China to keep N. Korea in check as much as it could. That is all over now. Don't worry...it is all symbolic.
The bottom line is the U.S. stuck it's nose where it didn't belong. And we have gone from a typical 'feel good' action by America, which America loves to posture, to a challenge against our denuclearization policies with a threat of deadline if we don't. Trump should have vetoed the bill.
Just google "N. Korea sets Christmas deadline for U.S."
Good-Ole-Rebel