From 2 particular books I've read on pirates and their way of living: Gabriel Kuhn's 'Life Under The Jolly Roger' (a more recent analysis) and Alexander O Esquemelin's 'The Buccaneers Of America', (a contemporary account), the pirate's diet has been written about in some depth.
Kuhn writes about a pirate dish called 'salmagundi', which is: 'meat of any kind - including turtle, duck, or pigeon - was roasted, chopped into chunks, and marinated in spiced wine. Imported salted meat, herring, and anchovies also were added. When ready to serve, the smoked and salted meats were combined with hard-boiled eggs and whatever fresh or pickled vegetables were available, including palm hearts, cabbage, mangoes, onions, and olives. The result was stirred together with oil, vinegar, garlic, salt, pepper, mustard seed, and other seasonings.'
While that sounds appealing, 'crackerhash' does not. Broken up ship's biscuit shaken in a bag with the week's leftovers, eaten in times of scarcity. Esquemelin who writes from first hand experience, describes the food available and the cooking and preparation methods of the buccaneers on the islands of Hispaniola and Tortuga: 'They have sweet potatoes in the morning for breakfast, served with butter, lemon juice, lard and red peppers. Some of these sweet potatoes are put aside to make a drink. The planters cut them in slices in a crock and pour on hot water. The liquor is strained through a cloth into a cauldron, after two or three days it begins to ferment. It makes a very good and nourishing drink, with a sour taste which is not unpleasant. They call it 'maby', a name learned from the Indians. They cook two meals a day of this meat (pork or turtle), without rationing. When it is boiled, the fat is skimmed off the cauldron and put into little calabashes, for dipping the meat in. The meal consists of only one course, and often it tastes better than the food to be found on a gentleman's table.
Of course pirates are renowned for drinking, and a common concoction, 'Rumfustian' was a blend of raw eggs, sugar, sherry, gin, and beer.......with no rum.