Quick question: why were they promised they'd fire no guns?  (or perhaps more strictly, why did they buy into that?)  Surely they knew as pirates and as crews after American gold that combat was almost guaranteed?  What were they hoping to do?!

Naval funerals involve firing one or more of the deck guns as a salute to the dead (the main guns were properly called the cannons, guns were for anti-personnel use). Paired with the phrase “shed no tears”, and with the wartime context, gives the interpretation that the American weapons would be ineffective and the crew would survive.