The coast from Ujung Batumamak (Batu Mamak) , the SW extremity of Teluk Tapanuli, trends in a S direction for about 49 miles to Tanjung Tabujung (Tabu-yung). There is a reef, with a depth of 3.7m, lying about 0.75 mile offshore, 13 miles S of Ujung Batumamak.
Sirene Reefs, one of the outermost dangers in this locality, consist of four heads, of which the westernmost and the southernmost, with 0.9m of water, sometimes break; there are depths of 1.4 and 6.9m on the other two patches.
Pulau Bintanah, low and fringed by a reef, should be given a wide berth. From Pulau Bintanah, a chain of reefs and shoals, some of which dry, extends 32 miles to the S. The positions of these dangers may best be seen on the chart.
An above-water rock lies about 1 mile offshore, 14 miles N of Tanjung Tabujung. Tabujung Road, located N of Tanjung Tabujung, is partly sheltered by Pulau Tangah (Pulau Tonga) and Pulau Si Dakah (Pulau Labu, about 4 and 1.5 miles, respectively, NW of Tanjung Tabujung.
Pulau Sarangbaung lies 10.5 miles NNE of the N extremity of Pulau Nias. There is a break in the reef on the SE side where boats can land at a village. The island is overgrown with coconuts and is visible for 12 miles.
Pulau Wunga, about 8 NM S of Pulau Mausi, is low andcovered with coconut trees. A large conspicuous tree, visible for 16 miles, is located on a small elevationnear the N end. The reef extending from the N side of the island is ordinarily marked by high rollers; on the S side ...