It is Hong Kong. There are pirates (who, if you look carefully at the tactics board near the start, apparently live on Skull Island). There are the Navy, who don’t have a lot of ships and apparently are losing the battle with the pirates before the movie even begins. Then there are the Police, who don’t really have anything to do with the pirates because they aren’t the Navy, but the Police and the Navy spend an awful lot of time fighting each other.
Jackie Chan plays the hero Sergeant Dragon, who starts in the Navy but is transferred to the Police when the Navy is decommissioned (long story). There are shenanigans and scrapes, some of which require the good Sergeant to do martial arts.
There is a stunt in this movie that involves Jackie allowing himself to fall from the hand of a town clock, through several awnings and onto a sand landing. Apparently he did this stunt no less than three times before agreeing they had a version good enough to include.
It is, of course, a very good movie for many reasons.