John Hamilton Moore

John Hamilton Moore was a Scottish-born teacher of navigation and a hydrographer who lived from 1738 to 1807. A portrait held by the National Galleries of Scotland identifies him as a teacher of navigation and hydrographer to the Duke of Clarence, showing the kind of reputation he built in maritime circles.

He is chiefly remembered for books such as The Practical Navigator and The New Practical Navigator, works designed to make navigation more usable at sea. Library records for his books describe them as complete systems or epitomes of navigation, with tables for finding latitude and longitude and examples drawn from shipboard journals.

Moore's influence lasted well beyond his own lifetime. Later accounts of The American Practical Navigator describe his manual as one of the leading navigational texts of the late 18th century, even as later navigators revised and corrected parts of it. That mix of usefulness, ambition, and real-world impact is a big part of why his name still appears in the history of navigation.