Editing Periplus (section)

==''Rahnāmag''==
[[Persia]]n sailors had long had their own sailing guide books, called ''Rahnāmag'' in [[Middle Persian]] (''Rahnāmeh'' رهنامه in [[Modern Persian]]).<ref>{{cite book |last1=Dehkhoda |first1=Ali Akbar |first2=Mohammad |last2=Moʻin |year=1958 |title=Loghat-namehʻi Dehkhoda |location=Tehran |publisher=Tehran University Press: Rahnāma }}</ref>

They listed the ports and coastal landmarks and distances along the shores.

The lost but much-cited sailing directions go back at least to the 12th century. Some described the [[Indian Ocean]] as "a hard sea to get out of" and warned of the "circumambient sea," with all return impossible.<ref>{{cite book |title=Civilizations: Culture, Ambition, and the Transformation of Nature |first=Felipe |last=Fernandez-Armesto |location=New York |publisher=Free Press |year=2001 |isbn=0-7432-0248-1 |url=https://archive.org/details/civilizationscul0000fern |url-access=registration }}</ref>