The Kitab-i Bahriye (Book of navigation or maritime matters) is an important portolano or book of sailing directions. The charts are based on the tradition of the isolario, introduced by Cristoforo Buondelmonte in 1420 and developed later by Bartolommeo dalli Sonetti and Benedetto Bordone. The work is divided into chapters, each detailing a specific location or region of the Mediterranean and accompanied by a chart. In the prologue Piri Reis explains that he chose to produce this work following the enthronement of Sultan Suleyman in 1520, when many individuals chose to present works to the monarch to gain favour, fame and honour. Piri Reis produced two versions, the first in 1521 (the version present here) and a second revised version in 1526. Both versions survive in a small number of manuscripts by different copyists (see literature below), although none in the hand of Piri Reis are known. The number of charts in the extant manuscripts varies owing to later copyists omissions or inclusions of new charts and views. "The attention given to the elaborate script and decorative charts in this manuscript is more common to manuscripts of the second version. Perhaps it was transcribed to commemorate one of the treaties between Turkey and the European powers in the early eighteenth century." (Harley & Woodward, p.291, n.18)

This work provides important information to naval commanders to enable them to navigate safely around the Mediterranean. Each chapter describes landmarks and the layout of harbours, warns of dangerous rocks, shoals or reefs, and occasionally includes distances or depths. Along with anecdotes and local histories, Piri Reis describes winds and informs the sailor where to find shelter and fresh water, together with military information regarding castles and the fortifications of ports.