Pirates wore what they had on their backs, until they stole something better. You would have seen crewmen in the peasant dress of the era, T-tunics and slacks for many. Evidence of pirate dress has been found; a leather jerkin was recovered from the wreck of the Mary Rose, King Henry VIII's great ship. This was an everyday piece of clothing for a working class man. Once a pirate made their fortune, she or he would dress very flashy and well above their station in life. In a later post here, we'll have knitting pattern for a hat and scoggers, found on the Mary Rose wreck.
Food could be bad or good. For those who traveled close to the shore, a common practice in the Middle Ages, when the galley ran low a stop in port to trade for food was possible. By the time of cross Atlantic trips, food had to be transportable. Hard tack, salted pork and fish were on the menu. Water was kept in large barrels and went bad fast. Alcohol was safer to drink. That being said, rum was NOT a drink in this time period. It was invented in the seventeenth century from molasses.
Ships will be up next, on A Pirate's Life!
(From my SCA class, So You Want to be a Pyrate.)