The coast between Tanjung Siapiapi and Tanjung Pertandangan, about 20 miles SE, is indented by a large bay fouled by shoals.
Several navigable channels lead through these shoals to the mouths of the Sungai Kuala Kualu and the Sungai Panai.
Tides—Currents
Between Tanjung Siapiapi and the drying banks off the mouth of the Sungai Panai, the flood sets into Teluk Piai Geul and follows the direction of the channel. The ebb sets on to Tanjung Siapiapi. Off Tanjung Pertandangan, the ebb sets to the E. Both off and within the river mouths, for some time after the flood begins, the surface water continues to run out while an undercurrent sets inward. Outside the 10m curve N of the banks, the flood sets SE. The greatest rate of the current outside the 10m curve is 2 knots; in the channels and rivers, the greatest rate is 3 to 4 knots. There is very little slack water at springs. Outside, each current runs for about 6 hours, but farther in the ebb runs for 7 hours and the flood for 5 hours. The currents turn about 45 minutes after HW and 30 minutes after LW. Off Tanjung Prapat and Tanjung Datu the flood sets towards the coast while the ebb sets strongly to the NW.
The coast forming the W side of Kualu Geul, which leads to the Sungai Kualu, has no distinctive marks, except a customs station on piles close off the village of Simendulang, about 7 miles S of Tanjung Siapiapa and some houses on piles off Tanjung Sibabi, about 1.7 miles farther S. The ...
Pulau-Pulau Aruah (Aruah Islands) is composed of two groups of small islands and some off-lying rocks which are located on a bank with depths of less than 20m. The S end of the bank joins an extensive mud bank lying adjacent to the Sumatera coast. Batu Utara (2°55'N., 100°36'E.), ...
Tanjung Percudian is fringed by mangroves and may be easily identified by the high trees behind it, decreasing very rapidly in elevation upon closer approach. Panipahan Village stands 4 miles S of this point. Between Panipahan Village and the entrance of the Sungai Rokan, about ...
Pyramid Shoal, which lies on the N side of the SE end of South Sands, has a least depth of 3.4m, hard sand, and is the most dangerous shoal in the area because of its depth and protrusion into the fairway. A lighted buoy is moored about 7 miles SE of Pyramid Shoal. A depth of about ...
Pulau Alang Besar, or Pulau Halang as it is also referred to, is
situated off the eastern coast of Sumatra in Riau Province, Pabupaten
Bengkalis. The island and associated coastline lie at Kuala Rokan.This small mangrove island and the nearby coastline contain extensive
habitats ...
Between Tanjung Pertandangan and Tanjung Sinaboi, about 56 miles ESE, the only points of identification are the river mouths. The mangrove covered coast is mostly muddy and low lying. The coastal bank, as far out as the 10m curve, is marked by fishing stakes and enclosures. Fishing ...
The coast between Tanjung Siapiapi and Tanjung Pertandangan, about 20 miles SE, is indented by a large bay fouled by shoals.
