Since ancient times until today, the Persian Gulf has been an important water way of the world. Its importance has been not only to perform as a route for transportation of commodities, but also as a way for transfer of cultures. Seafaring from the Persian Gulf to the Indian Ocean reached the peak of growth and prosperity in the early centuries of Islam, especially the tenth and eleventh centuries AD. The present thesis is dedicated to the study of customs and traditions related to these great activities. Most of the information of this thesis is collected from the Islamic geographical sources, which show that the Islamic merchant community composed of Iranians, Arabs, Indians, etc. who were acted in this field. Among them, Iranians were one of pioneers in seafaring and shipping since ancient times, and in the Islam era, Muslims became heirs of the Iranian legacy. Hence, Iranian traditions have had a deep influence in the Muslim seafaring and shipping technology. Originally, many of the symbols and material and mental culture of seafaring in the Persian Gulf are innovations of Iranians. The existence of Persian words such as Rahnamah, Bandar, Nakhoda, is an evidence to this claim. In general, the innovations of the people of the region in the fields of shipping and navigation, such as the preparation of guidebooks, the invention of navigation tools and special devices for determining distances, lanterns and local calendars in the centuries before and after Islam indicate the existence of a rich and deep culture in seafaring in the Persian Gulf.