Tokong Belanda, a low rock, lies about 1 mile WNW of the NW extremity of Assan.
Mudu lies about 1 mile SSW of Assan.
Reefs extend about 0.5 mile from its NW and W sides.
A 5.7m patch lies about 1.2 miles W of the N extremity of Mudu.
A drying reef extends about 0.7 mile SSW from the island.