China now has the largest fleet in the world by hull count.

They're still in the process of building up their carrier fleet but it will be able to match the Pacific fleet within the next decade.

I think any discussion on which fleet could destroy the other would be irrevocably tainted by jingoism and the fact that there hasn't been a serious naval engagement in eighty years, but the main point is that this weird idea people have that the US Navy is the undisputed king of the ocean is the kind of arrogance that has been punished countless times in history.