Since the 13th century, it is seen that the number of navigation charts, portolan atlases and portolan texts in the Mediterranean has increased. The Ottomans, who inherited the Mediterranean maritime tradition, started to produce new works in the field of cartography by following the Islamic geography knowledge and European geography and cartography technique and tradition since the 15th century. In the 16th century, they reached the peak of maritime cartography with Piri Reis. Kitab-ı Bahriye (Book of the Sea) by Piri Reis is an encyclopedic portolan atlas describing the entire Mediterranean. However, portolans are not just works containing maps. Various navigation guides prepared for sailors have also been expressed as portolans in the Western literature since the 13th century, although they do not contain any maps. The Portolan texts, which contain uniform, short texts consisting of navigational routes and distances between ports, have guided sailors for years. The subject of this article is a portolan text, which does not contain any maps and explains the distances between ports with their routes, in the booklet named Tuhfetü'l-Esrâr fî Tarîki'l-Bihâr, written by Mehmed Reis, an Ottoman sailor. The work consists of five chapters covering the entire Mediterranean and the Black Sea. It was used by Ottoman sailors as an alternative resource in addition to Kitâb-ı Bahriye, with the different information it provided about the Mediterranean and the additional chapter on the Black Sea. In terms of these features, Tuhfetü'l-Esrâr is a portolan booklet that has never been seen before in the Ottoman maritime literature. Here, a review of the text has been made and an edition critique has been published based on its different manuscript copies.