Sailing Guide

Sumatra W coast (Indonesia)

Sumatra W coast (Indonesia)

Characteristics

Description

On the W coast of Sumatera there is a high, rocky coast, or if there is a strip of sand by the sea, the land rises rapidly behind it to the neighboring hills.
Numerous small streams discharge their waters on the W coast, but most of them are barred and only navigable by small craft. Nearly the whole coast is inaccessible due to heavy surf.
The routes along the W coast of Sumatera may be considered as three in number, but the outer route may be said to be free from danger. The coast is reported to be only partially surveyed.
Vessels should keep to the sea until abreast the desired port before hauling in.

The route to the W of all the islands, in the open sea, is thebest of the three, especially for vessels not intending to touch at any of the W coast ports.

The middle route is the space between the chain of large islands in the offing and those small islands adjacent to and interspersed along the coast. It ranges from 10 to 30 miles distance from the coast of Sumatera.

The inner route is that close along the coast and between some of the islands and dangers off it. Like the middle route, it should seldom be chosen; but as there are in many places moderate depths for anchoring, it is preferable in that respect to the middle route.

Vessels visiting many of the ports are obliged to use it, but considerable risk is run when taking this route at night; those using it are generally obliged to anchor at sunset.

Winds—Weather

The influence of the Southwest Monsoon and the Northeast Monsoon are felt on the W coast of Sumatera as far S as 2°N, S of the Indian Ocean monsoons, but from Ujung Raya to 4°N the winds are quite different from those between 4°N and 2°N.
Between Ujung Raya and 4°N, the Southwest Monsoon prevails from May to October, and the Northeast Monsoon, from December to March. During the height of the Southwest Monsoon, the sea breeze prevails at times during the night. Generally speaking the land winds are clearly perceptible by the deflection of the wind to SE or N during the night. Squalls are frequent during the monsoon, and there is often a considerable sea along this coast. It is somewhat hazy at times.
The Northeast Monsoon period is from December to March, and it is less strongly marked. When the monsoon has fairly set in, there is usually a gentle S breeze in the morning, followed by a calm, and in the afternoon a light breeze. After sunset comes, the land wind prevails all night. Between 4°N and 2°N is the region of calms and light variable winds.

The influence of the monsoons only appears in a W tendency of the day wind from March to November, and an E tendency from November to March; at night, except in January and February, there is always a N tendency in the wind.

In April, SW and NW winds are most prevalent, both night and day. From May the NW winds become more prominent.

During the following months they increase and reach their maximum in October; at times these winds cause a considerable sea. August is marked by a frequency of NE winds. At night, the winds from May to November are from NW to NE.
From November to January, the wind is variable in the daytime; at night it is generally from NE to E.

Tides—Currents

The tides on the W coast of Sumatera are chiefly semi-diurnal in character and of small range, rarely exceeding 1.2m.

The current off the W coast of Sumatera sets mainly NW at a maximum rate of 2 knots near the 200m curve. It seldom sets SE, but may sometimes set onshore. Beyond 8 miles from the coast, the surface current caused by the wind attains a maximum rate of 1.25 knot with NW winds and 1 knot with SE winds.

North of the Equator, the current outside the islands may sometimes be the reverse to that flowing between the islands and the coast.

Pilotage

Pilotage is compulsory for all the ports of the Republic of Indonesia at which pilots are available.
Experience has shown that little confidence should be placed in the natives who offer themselves as pilots on the W coast of Sumatera for ports seldom visited. Signals for a pilot are in accordance with the International Code of Signals.

Regulations

An extensive prohibited area, in which fishing and other activities not associated with the innocent passage of foreign vessels, has been established off the coastline of northwestern Sumatera and is bounded by lines joining the following positions: a. 2°05.6'N, 96°38.0'E. (Pulau Babi) b. 1°55.0'N, 96°29.0'E. c. 2°51.0'N, 95°13.9'E. d. 2°57.0'N, 95°11.0'E. e. 4°48.0'N, 95°10.0'E. f. 5°43.2'N, 94°46.5'E. g. 5°51.0'N, 94°46.7'E. h. 6°13.5'N, 94°59.5'E. i. 6°16.0'N, 95°10.1'E. j. 5°40.4'N, 96°00.5'E. k. 5°29.0'N, 96°49.4'E. l. 5°29.2'N, 97°33.5'E. m. 5°01.0'N, 98°03.4'E. n. 4°33.8'N, 98°25.9'E. (Ujung Tamiang)

This prohibited area does not apply to foreign vessels supporting offshore terminals. Mariners should consult with local authorities for further information.

Caution:

The coastline is deeply indented, forming numerous bays, none of which, however, N of Sibolga, afford complete shelter during the Southwest Monsoon.
There are many visible and sunken dangers off the coast, but N of Ujung Raja, they do not extend to any great distance. South of that point they extend from 20 to 30 miles.

Many dangers no doubt exist that are not charted; caution is necessary at all times. Many of them are steep-to coral reefs, so that soundings will give no warning; a good lookout aloft should be kept during daylight, and vessels should proceed only at a moderate speed when navigating in the vicinity of dangers. Soundings, however, should not be neglected.

As a result of cataclysmic damage created by the tsunami of 26 December 2004, ports in this sector may be closed; depths, sea bed topography, and buoyage may not be as charted. Mariners are urged to contact local authorities for the latest information.

1/02/2012
Update
Jojo
Share your comments about "Sumatra W coast (Indonesia)"

Localisation

To precisely geolocate this site. Update if necessary.
Sites around Sumatra W coast (Indonesia)
Flying distances - Direct line

Strait of Malacca (East)

The Strait of Malacca is a narrow, 805 km stretch of water between the Malay Peninsula (Peninsular Malaysia) and the Indonesian island of Sumatra.Singapore Strait is the area lying between the S coasts of Malaysia and Singapore Island on the N side and the coast of Sumatera on ...
25 Jan 12

Kepulaun Mentawai (Mentawei islands) (W Sumatra)

Kepulaun Mentawai consists of four large inhabited islands, namely Siberut, Sipura, Pagai Utara, and Pagai Selatan, and of several smaller islands, which are not inhabited.
They are of volcanic formation and earthquakes occur from time to time. They are hilly.
The temperature ...
7 Feb 12

Sunda Strait

The Sunda Strait (Indonesian: Selat Sunda) is the strait between the Indonesian islands of Java and Sumatra.
It connects the Java Sea to the Indian
Ocean.
1 May 17

Pulau Simeulue (W Sumatra)

Pulau Simeulue, the northernmost of the large islands off 150 km of the W coast of Sumatera, lies about 65 miles from the coast.
It is hilly with Sibau, the highest peak being 625m high.
The coasts are mostly rocky, and there are many off-lying islands, islets, and reefs.
The ...
4 Feb 12

Pulau Nias (W Sumatra)

Pulau Nias, the largest of the islands at 125 km off the W coast of Sumatera, is hilly and from E appears like a chain of mountains of varying height. It has hardly any conspicuous peaks, but Maziaja Mountain, 432m high in the N portion, is noticeable along with three somewhat lower ...
6 Feb 12

Pulau pulau Batu (Kepulauan Batu) (W Sumatra)

Pulau Pulau Batu (Kepulauan Batu), forming the S side of Great Channel (between Pulau Nias and Pulau Pulau Batu), consists of three large islands, Pulau Tanahmasa, Pulau Tanahbala and Pulau Pini, with numerous islands fringed by extensive coral reef.
7 Feb 12

Pulau Banyak (Banjak) (W Sumatra)

The Banjak Islands, consisting of a group of islands more than 50 in number, extend from 13 miles NW to 38 miles W of Singkil. The three largest of the islands are Pulau Toeangkoe, Pulau Bangkaroe and Pulau Oedjoeng Batoe, besides which there are many islets with deepwater channels ...
4 Feb 12

Selat Siberut (W Sumatra)

Selat Siberut, between Pulau Bojo and Pulau Siberut, is about 21 miles wide.
Selat Siberut is the passage usually taken by vessels bound to Teluk Bayur from N.Low-powered vessels from the Indian Ocean bound to Selat Sunda between May and september, and all vessels bound N from ...
7 Feb 12

Pulau Enggano (SW Sumatra)

Pulau Enggano, the southernmost of the large islands fronting the W coast of Sumatera, lies about 60 miles W of Sumatera.
Pulau Enggano is about 20 miles long and about 10 miles wide.A range of hills runs through the island from NW to SE. The hills extend down to the sea along ...
7 Feb 12

Pulau Marbau (E Enggano)

Pulau Marbau, an island about 2 miles S of Pulau Dua is also covered with trees and surrounded by a reef, which on the W side extends but a short distance. There is a deep, narrow passage apparently between the reef off the S side of Marbau and the reef which extends SE of Tanjung Kahoabi.
7 Feb 12

Pulau Musala (W Sumatra)

Pulau Musala or Musalar lies in the W approach to Teluk Tapanuli.
At its NW end is a conical mountain, about 451m high, with a prominent tree on its summit.
There is a remarkable waterfall at the NW end of the island issuing from a hill with an elevation of 55m; it is a good ...
6 Feb 12

Gosong Makasar (W Sumatra)

Gosong Makasar (Makasser Reef), with a depth of 0.6m, lies about 12 miles SSE of the S extremity of Pulau Bodjo. It is easily recognized in the daytime by the high breakers on its shallow portion.
The reef extends 1 mile beyond the breakers.
7 Feb 12

Karang Posumah (Van Bylandt Reefs) (W Sumatra)

Karang Posumah consists of two patches, located about 7 miles ENE and E, respectively, of Pulau Bodjo; they have depths of 4.9 to 5.5m.
The SW side of the bank is very steep-to, but the NE side is more shelving. The shallowest parts may occasionally be distinguished by the swell, ...
7 Feb 12

Pulau Bodjo (W Sumatra)

Pulau Bodjo, lying about 2 miles S of the SE extremity of Pulau Tanahbala, is densely woodedand about 150m high. It is fringed by a steep-to reef which nearly dries, extending about 0.3 mile offshore in places.
A light is shown from the S side of the island.
7 Feb 12

Ujung Masang (W Sumatra)

Ujung Masang is low, with a reef stretching out about 0.5 mile and should not be approached in depths of less than 31m.
The Sungai Masang enters the sea at the point.
7 Feb 12

Karang Sirene (Sirene Reefs)

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.
7 Feb 12

Ujung Tuan (W Sumatra)

The coastal plain between the Sungai Singkil and Udjung Tuan, about 156 miles SE, is generally narrow, being backed by mountains with numerous peaks. Ujung Tuan is a rocky point. A 175m hill, with a remarkable broad conical summit, lies close SE of the point.To Udjung Tuan, about ...
7 Feb 12

Pulau Temang (W Sumatra)

Pulau Tamang (Pulau Temang) is an easily-identified hilly island (Area:10Km²with an average elevation of 1 m above the sea)  located at the SE extremityof Teluk Batahan, about 1 mile from the coast.
It is fringed by areef except at its W end, where there is a depth of 11m ...
7 Feb 12

Ujung Sikarakara (W Sumatra)

The coast between Tanjung Tabujung and Ujung Sikarakar, about 14 miles S, is fronted by many dangers, some of which lie just within the 10m curve.
Natal Road that lies off the coast between Ujung Sikarakara and Ujung Rakat, about 6 miles S, is open W and is encumbered with many ...
7 Feb 12

Bengkulu road (W Sumatra)

Bengkulu is the capital of the Bengkulu district and the headquarters of an administrator. The Bengkulu River mouth discharges into the bay about 2 miles NE of the town.
Bengkulu Road may be considered as lying between Ujung Coko (Ujung Parit) 4.5 miles N of Bengkulu and about ...
7 Feb 12

Ujung Tabuyung (W Sumatra)

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.
6 Feb 12

Karang Makassar (E Nias)

Makassar Reefs are four isolated dangers, with depths of 3 to 8.2m, and deep channels between them.
They lie from 1.75 to 7 miles S of Sumabawa, and from 6 to 7 miles offshore. They are marked by breakers or a heavy swell.
6 Feb 12

Tanjung Hele (S Nias)

Tanjung Hele, the S point of Telokdalam, lies about 6 miles E of Teluk Lagudri.
A reef marked by discolored water and very high surf, extends SE from Tanjung Hele, which should be rounded at a distance of at least 1 mile.
6 Feb 12

Tanjung Tedulehu (Tedu Ichu or Todojghu) (E Nias)

From Telok Dalam, the coast trends NE for about 6 miles to Tg Tedulehu (Balo Todojghu, Ujung Tedu Ichu, a low point covered with coconut trees.
A number of villages lie scattered along this stretch of coast. A narrow reef fronts the shore, preventing loading in most places. With ...
6 Feb 12
Local Area

Sumatra (Indonesia)

Sumatra (Indonesian: Sumatera) is an island in western Indonesia, westernmost of the Sunda Islands.
The longest axis of the island runs approximately 1,790 km (1,110 mi) northwest-southeast, crossing the equator near the centre. At its widest point the island spans ...
7 Jan 12

Indian Ocean

The Indian Ocean is the third largest of the world's oceanic divisions, covering about 20% of the Earth's water surface. It is bounded on the north by Asia (including the Indian subcontinent, after which it is named); on the west by Africa; on the east by Indochina, the Sunda Islands, ...
6 Apr 12
During your navigation, remember to update the data. If a harbor, marina or anchorage is missing, create it. Thank you for all boaters.