It's not that complicated. In port, you have to let people and equipment within your defensive perimeter. At sea, it's not the case. If an unknown vessel closes within X range without communicating will be destroyed.
====
True, but these speedbaots closed to within 200 yards on the open sea. On the released video the ship horn was wailing and it appeared the chain of command was not reacting quickly enough, or at least was confused.
To say there was no threat here is simply wrong imo.
I also agree that this incident is clearly being used by politicians to support their agendas, thats why the Iranians are so dangerous. Iranian stupidity, as exemplified in the incident, will trip the wire of war that has been set by the US.