The border follows this river briefly down to the Shatt al-Arab, the thalweg of which it then follows out to the Persian Gulf at the "lowest point of low water" at the mouth of the Shatt al-Arab at  (WGS84).
The border follows this river until it reaches the Shatt al-Arab. From there, it continues along the thalweg towards the Persian Gulf, following its lowest level during low tide at the Shatt al-Arb's mouth, which is situated at (WGS84).