Iran is videoing these incidents. That is really telling.
They are trying to set up the Navy in a way that it looks like the Navy fires first and sinks/kills Iranians. This is all about propaganda or worse.
As I have said elsewhere, Iran recently launched a submarine and has held Naval exercises where small boats launch anti-ship mussels.
If and when the Iranians provoke a US Navy response that is more than a warning shot, I hope the the US Navy has enough military assets in place to make sure that every potentially hostile or video taping Iranian military asset within 200 miles is destroyed along with the small speed boat.
My suspicion is that they want to provoke one of three responses: (1) pictures of evil US Navy destroying Iranian vessel in international waters for no apparent reason; (2) documentation that Iran retaliated and sunk a US Navy vessel after Iran was attached by such a vessel; or(3) capture of a US Navy vessel (ala North Korea USS Pueblo incident) after such vessel attached a small Iranian boat in international waters.
I feel that the Iranians are scum, but I do think that they have a method to their madness and it is madness to trifle with a US ship of the line in international waters.