DILIGENT STRAIT TO KOTARA ANCHORAG - 4252

Homfray Strait (12°15'N., 92°52'E.), an intricate, rocky channel connecting Elphinstone Harbor with Port Anson, separates Middle Andaman Island from Baratang Islands. Depths in the fairway are not less than 5m, except near the E entrance where the depths over the bar is very shallow.
The channel between North Passage Island and Strait Island is shallow and foul.
The channel between North Passage Island and Colebrooke Island is about 0.5 mile wide and has depths of 5.2 to 15.2m.  Small vessels with local knowledge can use this passage which is obstructed in places by reefs and shoals.
Colebrooke Passage (12°13'N., 92°53'E.) is 0.2 mile wide with depths of 7.3 to 15.8m. Its N part is shallow.
Anchorage.-Vessels can anchor about 0.3 mile SW of the jetty previously mentioned in depths of 8.2m, but the swinging room is restricted. Anchorage can be taken in a depth of 23.8m, good holding ground, about 10.3 miles W of Cross Point.
Well sheltered anchorage with good holding ground can be taken in a depth of 15.5m near the S end of Colebrooke Passage, with Cape Union in line bearing 065° with the center of Middle Button Island.
Caution.-A depth of 3.3m lies a little over one mile W of Cape Union, and a 5m patch lies about 0.8 mile SW of the same cape.
Anchorage can be taken in Rogolochang Bay (12°09'.5N., 92°50'E.) in depths of 7.3 to 9.1m, about 4 miles SSW of the S entrance of Colebrooke Passage.
A lumber camp, with a sawmill and a small woodshop, lies on the SW side of Long Island about 0.8 mile WNW of Cape Smith. A wooden jetty, with reported depths of 2.4 to 3m alongside, extends from the shore about 0.4 mile N of the camp. A trolley connects the two.
Mills Passage (12°15'N., 92°55'E.), between the S part of North Passage Island and Colebrooke Island, has a least width of 0.5 mile and depths of 5.5 to 19.8m. Numerous shoals and reefs obstruct the passage which can only be used by small craft with local knowledge.
Anchorage can be taken in a depth of 18.3m, good holding ground, about 0.3 mile off the coast of North Passage Island, with the NW point of that island bearing 029°, distant 0.5 mile.
Diligent Strait (12°10'N., 92°57'E.) lies between North Button, Middle Button, and the Strait Islands to the NW, and Outram, South Button, and the Wilson Islands to the SE.
Depths in the fairway of the strait range from 8.5 to 53m.  The shallowest depth of 8.5 lies about 1.8 miles E of the S end of Strait Island and a 9.7m patch lies about 0.5 mile farther E. Anchorage can be taken by small vessels with local knowledge close off the reef on the S side of the island.
South Button Island (12°13'.3N., 93°01'5E.), about 3 miles S of Middle Button Island, is 36m high and formed of large rocks, steep-to on all sides. A rocky head, with a depth of 10m, lies about 1 mile E and coral patch, with a depth of 3.2m, lies about 1 mile SE of the island. A light is shown from South Button Island.
Two Fathoms Rock (12°10'N., 92°58'E.) lies about 4.8 miles SW of South Button Island.
Directions.-Vessels approaching from the N should shape course, from a position about 2 miles E of North Button Island, to pass about 0.5 mile NW of South Button Island. When that island bears about 135°, course should be altered to the S until the S side of the island is in line bearing 055° with the NW extremity of Outram Island. This range should be kept on that bearing astern until the N point of Nicholson Island is seen open W of the W end of Wilson Island, bearing about 192°.  Course can then be altered to pass about 1.5 miles W of the latter island.
Vessels approaching from the S side should steer for Strait Island until the S side of South Button Island is in line bearing 055° with the NW extremity of Outram Island. This range should be steered until the E end of Middle Button Island bears 022°. Course should then be altered to pass NW of South Button Island and midway between Middle and North Button Islands and Outram Island.
Ritchies Archipelago
Ritchies Archipelago (12°03'N., 93°02'E.) consists of ten islands lying between the parallels of 12°16'N. and 11°56'N, with the N end of the group being separated from Baratang Island by Diligence Strait. All of the islands are heavily wooded.
Outram Island (12°14'N., 93°05'E.), the N island of the group, is reef-fringed on all except its W side and contains Outram Harbor in a deep indentation along its N coast. Some low rocks lie on the reefs which fringe West Point, the W entrance point of the harbor. Shoal ground extends 0.8 mile NE from this point, and 0.6 mile NNE from East Point, the E entrance point of the harbor.
Outram Harbor (12°15'.5N., 93°06'E.) provides good shelter from S winds. Small vessels with local knowledge can anchor in depths of 18.3m near the middle of the harbor, with the N end of Middle Button Island in line bearing 290° with West Point.
Ritchies Archipelago-NW Side.-Charka Juru, the strait separating Outram Island from Henry Lawrence Island to the S, has considerable depths throughout its length. Shoal ground extends about 0.8 mile S from South Point, the S end of Outram Island. Once this shoal has been cleared, a mid-channel course will lead through the strait.
The Wside of Henry Lawrence Island rises steeply to a ridge about 137m high. A narrow reef fringes the island.
Kwangtung Strait (12°06'N., 93°04'E.), the channel between Henry Lawrence Island and John Lawrence Island, has considerable depths in the fairway. The drying reefs which fringe both shores are usually visible.
Rocky Heads lie about 0.5 mile N of Briton Point, the N end of John Lawrence Island. Shoals and foul ground extend 1.5 miles NW from the NW coast of the island.
Wilson Island (12°08'N., 92°59'E.) lies W of the N part of John Lawrence Island and is separated from it by a narrow channel. Round Hill, which rises about 1 mile within the NW point of Wilson Island, is 216m high. Foul ground, marked by numerous coral heads, extends from the NW point of Wilson Island to Briton Point on John Lawrence Island.
Nicholson Island (12°06'N., 92°58'E.), separated from Wilson Island by a channel about 1 mile wide, rises to a height of 98m in its N part. The W side of the island is fringed by prominent steep-to white reefs. A reef extends about 0.3 mile S from the S end of the island. A shoal, with a depth of 3.2m, lies close S of this reef.
 Peel Island (12°05'N., 93°00'E.), low and bordered by dense mangroves, lies 0.5 mile E of Nicholson Island. The intervening channel is available only to small craft with local knowledge. The channel between this island and Wilson Island to the N is narrow and foul.
Havelock Island is the largest of the Ritchies Archipelago. There is an L-shaped jetty, with a dolphin close SE of its head, situated at Jetty Point from the N extremity of the island; there is a depth of 1.3m about 0.7 miles eastward.
Tadma Juru (12°03'N., 92°59'E.), narrow and deep, separates Sir William Peel Island from Havelock Island to the S. Both sides of the channel are fringed by shoals which extends up to 0.2 mile offshore in places. A detached patch lies on the S side of the channel, about 0.5 mile E of Stowe Point the N end of Havelock Island. Stowe Point is marked by a beacon. Yulutang, a conspicuous hill 167m high, lies 2.8 miles SE of the point.
Rosamund Shoal (12°04'N., 92°58'E.), a narrow coral ledge almost awash, lies about 0.5 mile N of the N end of Havelock Island. The ledge is difficult to make out.
Directions.-Vessels approaching Tadma Juru from the W, should pass S of Rosamund Shoal on a 090° course. When about 0.2 mile from the SW coast of Sir William Peel Island, course should be altered to 123°, maintaining a mid-channel course. When close to the E entrance of the strait, course should be altered to 073° toward the reef fringing the SW coast of John Lawrence Island. This steep-to reef is usually visible.  When close to the edge of this reef, course should be altered to 147°, which leads along the W edge of the reef and then E of Pilot Reef, which lies 1 mile S of the S end of John Lawrence Island.
Directions for proceeding in the opposite directions are given under the description of the E side of the archipelago.
Between Stowe Point and Doone Point, about 3.8 miles SW, the W coast of Havelock Island is slightly indented by an open reef-fringed bight. Anchorage can be taken off Jalebao, about 2.3 miles SSW of Stowe Point.
Between Doone Point and the S end of Havelock Island, about 9.8 miles SE, the coastal reef extends up to 0.5 mile offshore. Havelock, 1.3 miles SE of Doone Point, is a conspicuous hill, 164m high, at the W end of a bay. White cliffs, about 27m high, line the S end of the island. Sail Rock, 6.1m high, lies close off the S end of the island and appears as a sail on some bearings.
Ritchies Archipelago-E Side.-The N side of Outram Island and Charka Juru, the channel separating it from Henry Lawrence Island, have been previously described.
The E coast of Outram Island is fringed by a reef which extends up to 0.3 mile offshore. As previously stated, coral heads and foul ground extend about 0.8 mile S from the S end of Outram Island.
The E coast of Henry Lawrence Island is low, irregular, and bordered by dense mangroves. Reefs extend up to 1 mile offshore in places. A densely wooded islet lies on this reef about 4 miles S of the S end of Outram Island.  
Inglis Island (12°08'N., 93°07'E.) lies about 0.8 mile E of the wooded islet and is fringed by a drying reef on all except its NW side. This reef extends up to 0.5 mile off the NE coast where it terminates in two rocks, each about 1.2m high.  Small portions of the N and S points of the island have been detached by the action of the sea and appear as islets at high tide.
Inglis Shoals (12°06'N., 93°08'E.), two detached coral patches with depths of 6.8m and 8.7m, lie about 0.8 mile S and 1.8 miles SSE of the S end of Inglis Island.
During NE winds, sheltered anchorage can be taken in a depth of 12.8m off a sandy bay, close NW of Wreck Point, the S extremity of Henry Lawrence Island.
Tadma Bay (12°01'.5 N., 93°02'E.) lies W of Runnymeade Point, the S end of John Lawrence Island, and between it and Sir William Peel Island. It forms the S entrance of Paranga Juru, a narrow channel separating the two islands. It also forms the E entrance of Tadma Juru, which has been previously described.
Pilot Reef (12°01'.4 N., 93°02'E.), about 1 mile S of Runnnymeade Point, has a least depth of 3.8m. A narrow coral reef, as defined by the 10m curve, extends about 1 mile S from Pilot Reef.
Havelock Island, S of Sir William Peel Island, is reef-fringed.  Foul ground extends up to 1.3 miles E from its NE coast to within a short distance of the ridge which extends S from Pilot Reef.
Anchorage.-Anchorage can be taken in Tadma Bay, sheltered from all except S winds.
Directions.-Vessels approaching Tadma Bay from the S and E can clear Pilot Reef and the foul ground E of Havelock Island by bringing the W extremity of Sir Hugh Rose Island bearing 173°, and just open E of the E extremity of Neill Island. When the extremity of the reef extending S from Runnymeade Point is seen, course can be shaped to the NW into Tadma Bay.
Minerva Ledge (12°04'N., 93°09'.5E.), a detached rocky ledge with a least depth of 6.8m, lies about 4.5 miles ESE of Wreck Point. It lies near the outer edge of a bank, as defined by the 40m curve, that extends about 5 miles E from the S end of Henry Lawrence Island.
Vibart Shoal (11°58'.6N., 93°08'E.), narrow and steep-to on its E side, lies centered about 6.3 miles SE of Runnymeade Point. Depths over this shoal range from 15.6 to 18.3m
The island has been reported to be a good radar target up to 14 miles.
Several patches, with depths of 5.5 to 11.9m, lie in the channel between Neill and Sir Hugh Rose Islands. Vessels are advised not to use this channel because the bottom is very uneven.
Deep-draft vessels passing SW of Sir Hugh Rose Island should avoid a bank with depths of 16.5 to 18.3m, which lies between 1.5 and 2.5 miles SW of the island.
Andaman Strait (12°04'N., 92°47'E.), referring to the E entrance of that strait, lies between North Point, a 76m promontory forming the SE extremity of Baratang Island, and South Point, the NE extremity of South Andaman Island, about 2 miles SSW. From the 76m promontory the coast extends about 1.8 miles WSW to Entrance Hill, the N point of the inner entrance of the strait. This 30m high conical hill is conspicuous.
Andaman Strait Light is shown from the summit on North Point.
The general width of the strait ranges from 0.2 to 0.3 mile, but narrows to a width of 73m in places.
The strait has moderate depths, except for two ridges which span the strait, and over which the least depth is 3m. A bar, over which there are depths of 2.7 to 3.9m, obstructs the entrance from a position about 0.5 mile NE of Entrance Hill and South Point. The navigable width of the bar is about 183m.  A vessel with a draft of 4m has passed through the strait. The bottom throughout is of mud and sand.
A small isolated, rocky ledge topped by a 4m high prominent rock on it, lies about 0.5 mile SE of the 76m promontory. A detached shoal, with a least depth of 2.1m, lies about 0.5 mile S of the promontory.
A coral reef, which dries in places, extends up to 0.5 mile offshore between North Point and Entrance Hill.
A ledge of drying coral extends almost 0.5 mile NE from South Point. The coast between this point, and the S point of the inner entrance of the strait about 1.5 miles W, is bordered by foul ground which extends up to 0.3 mile offshore.
Oral Kaicha (12°11'N., 92°46'E.), a small island which lies about midway between the E and W entrance of the strait, can be passed on either side but the E side is preferred.
Anchorage can be taken in depths of 16.5 to 18.3m, mud, about 1.3 miles NNE of South Point.
The coast between South Point and Wedge Point, about 1.5 miles to the S, is fringed by a drying reef that extends almost 0.3 mile offshore.
Smyth Rock (12°02'.6N., 92°48'E.), the outermost danger off this section of coast, lies about 1 mile E of South Point and has a least depth of 3.3m.
Whitehouse Rock, which has a least depth of 3.6m, lies 1 mile E of Wedge Point. A shoal, with a least depth of 1.2m, lies midway between this rock and the point.
A rock, barely above water, lies 0.5 mile SE of South Point.  Rocks, which dry up to 1.2m, lie about 0.4 mile N and 0.3 mile NNE of Wedge Point.
Wedge Rock, 8.5m high and prominent, lies close S of Wedge Point.
Port Meadows (12°01'N., 92°46'E.) is entered between Wedge Point and Cape Persain, a little over 1 mile SW. The shores of the port are reef fringed and the low land is covered with mangroves. Cape Persain is the NE extremity of a fairly high hill which lies on a promontory separated from the coast by mangroves.
Duncan Island (12°01'N., 92°47'E.), 91m high and densely wooded, is connected to the shore W of Wedge Point by a drying shoal.
The entrance channel, which lies between Duncan Island and Cape Persain has a least depth of 4.5m.
The E and S sides of Duncan Island are fringed by above-water and sunken rocks which extend up to 183m offshore. A prominent 5.5m high rock lies close off the SW side of the island. A drying rock lies 137m SW of this rock.
The E side of the promontory forming Cape Persain is fronted by a drying reef that extends about 0.4 mile offshore.  This reef only extends about 183m offshore, E and N of Cape Persain. Some drying rocks lie on the reef.
A detached 4.5m patch lies about 0.2 mile E of Cape Persain.
A two-pronged pinnacle rock, with a least depth of 5m, lies on the S side of the approach to Port Meadows about 0.7 mile SE of the summit of Duncan Island. A dangerous wreck, marked by a buoy, lies on this rock.
The Patch, a shoal with a least depth of 7.3m, lies about 0.8 mile ESE of Cape Persain.
Anchorage.-Anchorage can be taken in depths of 16.5 to 18.3m, about 0.2 mile W of the W point of Duncan Island.  Anchorage can also be taken in a depth of 14.6m in the center of the SW part of the harbor, about 0.6 mile W of Cape Persain.
Directions.-Vessels should keep Cape Persain bearing 276° until the E end of Duncan Island is in line bearing 012° with Wedge Point. A course of about 292° then leads in mid-channel through the entrance. When Wedge Rock becomes visible, course can be altered to 000° for the E anchorage, or to 260° for the W anchorage previously mentioned.
A jetty extends from the W side of the promontory about 0.3 mile Wof Cape Persain. A lumber camp lies near the inner end of the jetty. The coast between Cape Persian and Point Crawley, about 0.8 mile S, and then to Kotara Point, about 1.5 miles farther SW, is fringed by a drying reef which extends about 0.5 mile offshore. Some drying rocks lie on this reef.
Kotara Anchorage (11°58'.5N., 92°45'E.) lies between Kotara Point and the N side of Kyd Island, about 0.8 mile to the S. This island is 237m high and rounded.
A least depth of 6.4m exists in the fairway with depths of 8.2 to 14.6m being found in the entrance.
Anchorage can be taken in depths of 6.4 to 7.3m, mud, about 0.5 mile SW of Kotara Point. Small vessels with local knowledge can anchor in depths of 7.3 to 8.2m, mud, in the outer part of an inlet about 1.5 miles W of Kotara Point.
Shoal Bay (11°56'N., 92°47'E.) entered between the SE side of Kyd Island and Cape Masy, about 1.5 miles to the SE, is shoal over most of its area. Depths of 5.8m are found in the narrow entrance channel decreasing to a depth of 5.2m about 1.5 miles within the entrance and to a depth of 1.8m at the entrance of Shoal Bay Creek.
The coast between Cape Masy and North Point, about 14.5 miles to the S, is bold and free from dangers. The land rises to form a broken ridge which parallels the coast at a distance of about 2 miles. Koyob, a peak which rises to a height of 459m, lies 6.8 miles N of North Point.