United States Naval Ships (USNS) are not warships. They are civilian cargo ships owned by the Unite States Navy, crewed by civilians, and unarmed.
They are lightly armed but not unarmed. And they do have military aboard.
exactly the point I was going to make..huge difference between USS and USNS..
Surely some of the crew or the officers are former navy. Even if not, they are still American males. Should have simply rammed the attackers. Get everybody under some decent cover from small arms and like the character D-Day from Animal House scream: Raaaaaaammmmming Speeeeed! Even if they couldn't run them over certainly the bow wash or wake would capsize the craft. Then just let them drown like rats. Sorry, didn't mean to call you Shirley.
They had a contingent of Marines embarked when they were serving as a detention ship, but they’re probably gone now. Given that they’re carrying ammunition that we’d rather not have fall into the pirates’ hands, it might make some sense to give them some new ‘cruise passengers’.