Is a pirate treasure buried in Bayport?

That's what Captain Sid, the owner of a souvenir shop, says. When Frank, Joe, and Chet meet Sid on their way to go sailing, he tells them about a pirate ship that sank off the coast of Bayport four hundred years ago..

As the boys head to the boat, they find a strange silver coin on the ground...then an old bottle with a treasure map inside...then a rusty musket ball -- the kind pirates used in battle! Could Captain Sid have been right about the shipwreck? Frank and Joe are baffled -- and it won't be smooth sailing until they figure out this whale of a mystery!

Genre: Mystery