The rich collection of books and maps of the Sylvia Ioannou Foundation includes an exquisite atlas made by the seventeenth-century Italian mapmaker Giovanni Battista Cavallini, who made and signed it in the port-city of Livorno in 1635. The coats of arms and the rich heraldic ornamentation of the manuscript inform us that it was made for Ferdinando II de’ Medici (1610-1670), Grand Duke of Tuscany and Grand Master of the Order of Santo Stefano. The aim of this essay is to describe in detail the composition and specific decorative aspects of the atlas and to place it within the artistic tradition of seventeenth-century manuscript maritime maps. I will first analyse the structure and content of the maps. Then I will decipher the specific iconography of the maps and evaluate the level of geographical information provided, thereafter offering some insight into the possible significance of the commissioning of this manuscript and the meaning of what I would call its ‘voluntary old-fashion style’, far from having practical use on board.