Dangerous Journey by David Drake

For 9 to 15 year An older man, Jonas, built and lives on a 30 foot, two masted, sail boat on which he sails the Caribbean Sea. On one outing he discovers a recently orphaned stowaway – 11 year old Carlos. The boy has information about a treasure left to him by his Great Grandfather – an old-time pirate – stashed on one of the islands in the Bahamas. The boy has a secret code they have to decipher in order to locate it. The two of them accept the challenge and undertake the search; one problem – so does Fidel, an evil modern-day pirate who also came by the information. They struggle to stay just one step ahead of him as he chases them south, in and around the Bahama Islands.