Extremely rare, this is a 1791 wall sized nautical chart or maritime map of the Baltic Sea by John Hamilton Moore. The map covers from the Gulf of Bothinia and the coast of Finland south to Pomerania, Prussia, and the Kattegat, and from Denmark east to the Gulf of Livonia. In modern terms, this map covers the Baltic Sea in the vicinity of Sweden, Finland, Estonia, Latvia, Lithuania, Poland, Germany, and Denmark. There are several inset plans detailing the Harbor of Riga, the Harbor of Carlshamn, the city of Riga, Geffle Haven, and Ahus Haven / Lando Hamn. There are countless nautical sounding throughout and series of 26 sore profile views decorate the upper right and lower quadrants. The large decorative title cartouche drawn and engraved by J. Stephenson appears in the upper left quadrants and exhibits a bucolic Scandinavian scene. One can only wonder if this is J. Stephenson is one in the same or a relative of the John Stephenson, a coal trade captain, who is known to have provided Moore nautical information to more that was eventually compiled into some of his more popular charts of the North Sea and Thames Estuary. This chart is exceedingly scarce. We have identified only two other examples, one in the collection of the Bibliotheque Nationale de France, the other in the Biblioteca Nacional de Espana.