Behind the scenesEdit
In Quest for Glory, East Fricana corresponds roughly with East Africa, Tarna is located in East Fricana and Egypt is located in North Fricana. However it is implied that the ancient Egyptians had been the ones that originally colonized Tarna. It is suggested that Egypt borders Tarna to the north in QFG5.
In earth's geography East Africa is bordered by the Indian Ocean to the east. Egypt lies in northeastern Africa but is usually categorized into North Africa. Egypt is bordered by the Red Sea.
It is possible that Azure Sea is a pun on the Red Sea, and Tarna's connection to Egypt.
It is also possible that Tarna is below real world Ethiopia since there are mountains to the north and Tarna is more tropical then the Sudan area. If this is taken into account the Azure Sea could also be the Arabian Sea.
Pretty much there is equal footing for the Azure Sea being the Red or Arabian Seas.