flows along the north coast of Panay past Bulacaue Point and the Gigantes Islands to Bulalaqui Point, the north point of Cebu, where it turns southward and meets the stream from the Pacific through Surigao Strait, about 6 miles south of the Camotes Islands; it also flows through Iloilo and Tanon Straits, in both of them meeting the flow which has entered from southward on the parallels of the north end of Negros and of Tajao Point, Cebu, respectively. The other branch turning to the south from the northwest point of Panay, and being joined midway by the stream setting eastward from Cuyos Islands or Linapacan Strait, continues coasting Panay and Guimaras Islands into Iloilo Strait until it meets the other branch described above. Between the Calamianes and the north end of Palawan the flood stream sets southeast and the ebb northwest. The flood stream entering by Balabac Strait turning north-northeast along the coast of Palawan spreads itself like a fan over the Sulu and Mindoro Seas from northeast to east, forming the current from west to east felt between Cuyos Islands and Panay, and also that which sets to the south of the Cagayanes, where it is said to meet the stream from Surigao Strait approximately in the meridian of the Cagayanes. In the Sibutu Passage the flood stream sets northward and westward; and also in the Sulu Archipelago the flood stream sets generally in the same direction, but takes many local directions among the islands. Through Basilan Strait the flood stream makes westward and passes up the west coast of Mindanao northward until it meets the flood stream from Surigao Strait about midway on the coast. In some places the tidal current seems to be influenced by a monsoon current. Along the Panay coast there is a constant northerly current which varies but little in strength with the change of tide. In the vicinity of Seco Island and Batbatan this current changes its direction to westward and then southwestward through the Cuyo Islands, thus forming a great eddy. A somewhat similar eddy exists in the Mindanao Sea southeastward of Bohol. The time of high water of the wave that enters from the China Sea seems to be from 10 to 12 hours and that which comes from the Pacific through the eastern and northern straits from 6 to 7 hours. Tide tables for western North America, Eastern Asia, and many island groups of the Pacific Ocean, including the Philippine Islands, are published annually in advance by the United States Coast and Geodetic Survey. This volume furnishes, at the nominal cost of 15 cents, United States currency, full tidal data for the ports of the Philippine Islands. It contains a table of full daily predictions of the times and heights of high and low waters for certain standard or principal ports along the coast; full explanations for the use of this table are given on page 8. The use of Table 2 of the Tide Tables should be known to every navigator. By means of this table the predictions given for the standard ports are extended so as to enable one to obtain complete tidal data for each day for stations only a few miles apart for the greater part of the coast, and with almost the same accuracy as though full predictions were given for all of these points. Instead of using the height differences of Table 2, however, a more accurate method is that of multiplying both high and low water heights at the standard port by the ratio of ranges for the given port to obtain the heights of the corresponding high and low water. The ratio of ranges is given in Table 2 of the Tide Tables. The minus sign before the predicted heights in the Tide Tables indicates that the water is below the plane of reference which is mean lower low water. The time of high or low water at any given port in Table 2 is found by taking the time of the corresponding tide for that day from the standard port for reference and applying to it the time difference for the given port from the third column of Table 2, adding it if the sign is plus and substracting if minus. Caution. In using the Tide Tables, slack water should not be confounded with high or low water. For ocean stations there is usually but little difference between the time of high or low water and the beginning of ebb or flood current; but for places in narrow channels, landlocked harbors, or on tidal rivers the time of slack current may differ by two or three hours from the time of high or low water stand, and local knowledge is required to enable one to make the proper allowance for this delay in the condition of tidal currents. The figures giver in Tables 1 and 2 of the Tide Tables are the times of high and low water, and these times are not necessarily the times of slack water. Current tables.-Beginning with the year 1927, current tables for San Bernardino Strait are included in the Pacific Coast Current Tables, published annually in advance by the United States Coast and Geodetic Survey. They may be obtained at any of the chart agencies, price 10 cents, United States currency. COASTWISE NAVIGATION The general routes usually followed by vessels coming to or leaving the Philippine Islands are shown in red on the index map of Coast and Geodetic Survey charts. Over The navigation of coral seas demands constant vigilance; aside from this the waters described in this volume present no unusual difficulty to the mariner. The lead gives little or no warning of the approach into danger, and the effect of uncertain and irregular currents is a constant source of danger on the longer courses. rocky bottom and on shoals the 10-fathom (18.3 m) curve should be considered the danger curve, as coral bowlders frequently rise from 3 to 4 fathoms (3.6 to 4.9 m.) above the general level of the shoal, and the surveys may not have found the least water in every case. The waters northward of Luzon and the north and northeast coast of Luzon have not yet been surveyed and are but imperfectly charted. Typhoon anchorages. During certain seasons of the year destructive cyclonic storms or typhoons are frequently encountered in the area described in this volume. Vessels seeking shelter from stress of weather will find that the following harbors offer excellent anchorage during typhoons. They are the more important harbors of refuge, but numerous other harbors offer shelter, and masters of vessels should use discretion in their choice of a typhoon harbor. Since typhoons usually give ample warning of their approach, together with their probable path, anchorage should be chosen which offers best shelter from the winds which will prevail during the coming typhoon. If in the vicinity of any of the following harbors, they should be given preference: North coast of Luzon: Port San Vicente. West coast of Luzon: Bolinao Harbor, Port Matalvi, Olangapo Harbor, Manila Harbor. Marinduque Island: Santa Cruz Harbor, Port Balanacan. Burias Island: Port Busin. South coast of Luzon: Sorsogon Bay. East coast of Luzon: Port San Vicente, Casiguran Sound, Hook Bay (Pollilo Island), Dahikan Bay, Lamit Bay. Lubang Island: Port Tilig. Mindoro Island: Soguicay Bay. Romblon Island: Romblon Harbor. Ticao Island: Port San Miguel. Panay Island: Iloilo Harbor. Cebu Island: Cebu Harbor. Samar Island: Helm Harbor, Port Borongan, Pambujan Harbor, Port Aguirre (Canahuan Islands). For a general description of typhoons and practical rules for maneuvering in their vicinity, see appendix, page 342. DESCRIPTIONS AND SAILING DIRECTIONS ISLANDS AND CHANNELS NORTH OF LUZON Taiwan (Formosa) Island.-Goaram Pii (Nansha or South Cape), the southern extremity of the Island of Taiwan, is the usual landfall of northward-bound vessels from the Philippine Islands. An isolated rock with deep water around, stands up boldly close to the southeastern point. At 4 miles northwestward of the cape is a peculiarly rugged hill 1,035 feet (315 m.) high, from which the land slopes down gradually to the cape, the whole, with the exception of a few clearings, being densely wooded. Farther northward is a double-peaked mountain about 2,000 feet (610 m.) high. A fixed white light with a red sector-visible 20 miles-is exhibited 180 feet (55 m.) above high water from a white circular lighthouse on Goaram Pii. In answer to a vessel's fog signal, two guns are fired with an interval of 3 minutes between them, and if the vessel's fog signal is still heard the firing is repeated after an interval of 8 minutes. Vele Rete Rocks, about 9 miles southward of Goaram Pii (South Cape), Taiwan, are a group of rocks about 1 mile in extent, above and below water. The three highest, lying northwest and southeast from each other, are 15 to 25 feet (4.5 to 7.6 m.) above the sea. The depths near the rocks are from 39 to 78 fathoms (71 to 143_m.), except off the southern side, where at a distance of 1/2 mile the depth is 17 fathoms (31 m.). In bad weather the sea breaks heavily over these rocks. The channel between the rocks and Taiwan is safe, but very heavy tide rips, resembling the sea breaking over a shoal, are frequently experienced nearly the whole distance between them and the land. Bashi Channel is between the Batan Islands and the Island of Taiwan and connects the Pacific Ocean with the China Sea. This channel, frequently used by sailing vessels when making the eastern passage to China and Manila and sometimes by steamers trading between the United States, Japan, and Manila, is 52 miles wide between Y'Ami Island, of the Batan Group, and Little Botel Tobago Island, lying east of the south point of Taiwan Island, but its navigable width is much contracted by the dangerous Gadd Rock, which must be remembered when sea room is necessary to avoid the track of a typhoon. Gadd Rock lies 14 miles southward of Little Botel Tobago Island, and in the fairway of Bashi Channel, is about 100 yards across, with a least depth of 10 feet (3 m.), and 30 to 40 fathoms (55 to 73 m.) close around, deepening to 69 and 127 fathoms (126 to 232 m.) within 1 mile. At low water the sea probably breaks, but the locality is generally covered by violent tide rips and swirls, which extend more or less the whole distance to Vele Rete Rocks, off the south point of Taiwan 62012°-27-2 13 Island. These indications of its position are not always visible, and the vicinity of this danger should, therefore, be avoided. Heavy overfalls and discolored water have been passed through about 11 miles southward of Gadd Rock; no soundings were obtained, and bottom could not be seen from aloft; from this it seems probable that the tide rips and swirls extend southward of Gadd Rock. BATAN ISLANDS lie northward of the Babuyan Islands and consist of a chain of islands, mostly high, extending from latitude 20° 17′ N. to 21° 06′ N.; the channels among them are thought to be safe and free from danger. The physical characteristics of the larger islands indicate volcanic origin. fbayat, Batan, and Sabtan are particularly mountainous, with intervening valleys and plains sloping to the shore and well watered by small rivers. The smaller islands are generally low and rest on coral foundations. The climate of these islands is noted for its salubrity. The inhabitants possess many of the characteristics of the native races of Taiwan, and their peculiar language increases their exclusiveness. This has been strengthened by the ocean currents and consequent difficulties of intercourse with the mainland of Luzon southward. The chief industry is raising cattle, hogs, horses, and goats, which grow to a large size, and, on account of their superior quality, are exported in large numbers to the mainland. Y'Ami Island, the northern island of the Batan Group, is about 1/2 mile in extent, 600 feet (183 m.) high, and has an islet lying off its southwest point. North Island, lying 11⁄2 miles south-southwestward of Y'Ami, is high and steep, except off its eastern side, where three islets and some detached rocks extend 200 yards. The channel between Y'Ami and North Island is safe, and shows soundings with rocky bottom, but too deep for anchorage. Mabudis Island, lying 81⁄2 miles southward of North Island, is about 11⁄2 miles long in a northeast and southwest direction, high and steep-to. The channel between it and North Island is wide and free from danger, except that breakers have been reported about 2 miles 229° (SW. % W. mag.) from North Island. Siayan Island, lying about 1 mile south-southwestward of Mabudis Island, is about 1/2 mile in diameter and has several detached rocks off its northeast side, rendering the channel between it and Mabudis unsafe. Ibayat Island, the largest of the group, lies 4 miles south-southwestward of Siayan and 14 miles north-northwestward of Batan. It is about 8 miles long in a north-northeast and opposite direction, and has an area of 26 square miles. Mount Santa Rosa, at the north end, is 680 feet (207 m.) high, and Mount Riposet, in the southeastern part, is 900 feet (274 m.) high. The island, from seaward, presents a barren outline, defying debarkation to any but those acquainted with the locality, and is, moreover, without anchorage; the interior is, however, highly culti vated and exhibits many patches of good timber trees. The waters |