As it turned out, the book recounts the voyages of two ships, Duke and Dutchess, which set off on an expedition in 1708. Ironically, the expedition leader Captain Woodes Rogers was later sent to the Bahamas as Royal Governor in 1718 with the mandate of getting rid of pirates. The book also recounts the rescue of Alexander Selkirk, a man who had been marooned on an island for four years and who was the inspiration for the 1719 book, Robinson Crusoe.
Dvorsky reports that narratives of voyages were popular reading material at the time. While no one can say if Blackbeard, aka Edward Teach, read the book himself, it’s likely someone on his crew did, either for fun or to gather ideas for places to pillage or insights into pirate-hunters of the Royal Navy.
Kristin Romey at National Geographic writes that historically speaking, some members of a pirate crew needed to be literate. That’s because, to plunder the high seas, they needed to read navigational charts. There are also accounts of pirates stealing books from ships and there’s even some evidence that Blackbeard kept a long-missing diary. 
Kenyon tells Gannon that finding the book might also be a political statement. It’s likely that pages were torn from the book and used as wadding in the cannon. Someone could have randomly grabbed the book during the heat of battle. It’s also possible that Blackbeard and Rogers knew of one another or tangled with each other. The same year Rogers arrived in the Bahamas, Blackbeard departed the area, heading to North Carolina. “We’re starting to formulate ideas about whether these two men knew each other,” Kenyon says. “Were they connected somehow? Did Woodes Rogers’ arrival spark Blackbeard’s imminent departure? Was this act of tearing up a book of his a statement of some sort?”
It’s probably impossible to know for sure. Romey reports the conservators are currently working with the North Carolina Department of Natural and Cultural Resources Division of Archives and Records and experts at the Winterthur/University of Delaware Program in Art Conservation to preserve the fragments.  They hope they will go on display sometime later this year as part of celebrations commemorating the 300th anniversary of Blackbeard’s death.