Ghost of the Noonday Sun, The (Vintage Paperback) by Sid Fleischman

If the pirates don't get you...their ghosts will! 

So begin the adventures of young Oliver Finch, born at the stroke of midnight. Believing that Oliver can spy out ghosts, Captain Scratch kidnaps him, bringing him aboard the notorious pirate vessel Bloody Hand.

The ship sails the high seas in pursuit of the ghost of Gentleman Jack, who paces his grave where the pirate treasure lies buried. A despicable pirate captain, a mutinous crew, a band of sly sea ghosts—Oliver is determined to outfox them all and get safely home. It's a tale of treachery, intrigue, and suspense!