A few shoulder fired missals and Barrett 50s would repeal any pirates. The problem now is that these ships are unarmed per maritime law, time to change the law. The boats the pirates have are faster, and they can shoot lines up and over the side to climb and board. Anyone going near the boarding lines to throw them over the side, are shot at with guns or grenades.
These merchant marines are taking water hoses to a gun fight. They are going to lose.
Personally I feel we need to go in and strafe or bomb the port cities that support these pirates. "OH, the innocents", you say. The innocents are the support staff, and future pirates in training. Need to put a stop to it once and for all.
We also need to watch for the Mother Ships that are out there. Once confirmed blow them out of the water.