Persian Gulf flooding of the basin started 15,000 years ago due to rising sea levels of the Holocene glacial retreat. This inland sea of some is connected to the Gulf of Oman in the east by the Strait of Hormuz; and its western end is marked by the major river delta of the Shatt al-Arab, which carries the waters of the Euphrates and the Tigris. In Iran this is called "Arvand Rood", where "Rood" means "river". Its length is , with Iran covering most of the northern coast and Saudi Arabia most of the southern coast. The Persian Gulf is about wide
Quoin Island (Persian Gulf) Quoin Island (Persian Gulf) Quoin Island (also known as "As Salamah Island" and "Great Quoin Island") is the largest of three islands of the As Salamah Archipelago. It is the northernmost landmass of Oman and the traditional "way point" used by ships to define the entrance or exit from the Persian Gulf. Once a ship is declaired a position of "Passed Quoin Inbound" the insurance rates for the ship will increase. The island has a triangular outline, is about 770 meters long and up to 530 meters wide, yielding an area of about 22 hectares. Quoin Island, Oman, is not