Flyntlock Bones. The Sceptre of the Pharaohs, Paperback/Derek Keilty

When young Flynn becomes too old to stay at the Baskervile orphanage, he applies for a job as cabin boy on the Black Hound. He doesn't expect it to be a pirate ship, but soon they are setting sail for the Seven Seas, on a perilous quest to recover ancient treasure bound by a magical curse.