The aim of this paper is to investigate one passage from Pseudo-Skylax's Periplus that explains that the Naro River is navigable for trieras. Through the critique of archaeological and written evidence and the use of deductive reasoning, the author reconstructs the relations between various polities on the South-eastern Adriatic from Archaic to Hellenistic period and the political and economic context of Periplus.. According to the new interpretations of the Periplusthat emphasize the authenticity of presented data, the author concludes that this information pertains to times of ‘pre-colonial’ encounters or perhaps even from times of early colonization (i.e. from 5th till mid 4th century BC), thus the mentioned trieras were probably Corcyran or Syracusian.