The channel is navigable only by small craft as the entrance is shallow.
Pulau Mantang, the W island, is low, overgrown with mangroves, especially on the S coast, and encircled by a reef that dries. The W side of the island is foul to a distance of about 0.2 NM.
On the N side of the island are the villages of Baru, Mantang, and Riouw.
Pulau Ranggas, a small rock island, thickly wooded and 50m high, is
about 0.7 mile long and 0.2 mile wide; it lies about 2 miles WNW of
From a distance this island looks very much like Southwest Hill on the SW end of Pulau Mantang. There is a channel between Pulau Ranggas and Pulau Mantang, but it is not advisable to use it without local knowledge.
Off W pulau Mantang lie several wooded islands.
The channel N of Pulau Mantang and Pulau Siulung, and the coast of Pulau Bintan N of Pulau Bunut has several islands and reefs lying in places 2.5 miles from Pulau Mantang.