MANILLA AND SOOLOO SEA. 



361 



STRAITS OF BALABAC. 



The Straits of Balabac lie at the western entrance to the Sooloo 

 Sea, occupying the space between the Island of Balabac on the north, 

 and the Islands of Banguey and Balainbangan on the south, a width 

 of 30 miles. The range of shoals and sand-banks, which extend 

 across the entrance and between the above islands, were examined 

 by the Expedition. It is believed that all the obstructions in these 

 straits were surveyed, and are laid down on the chart of the Expe- 

 dition ; but as our time was limited, and we were unfortunately 

 deprived of the use of the tender Flying-Fish, the examination was 

 not so thorough as I could have wished. To the north, in range 

 with the east side of the Island of Banguey, lie the largest number 

 of these dangers to affect its free and safe navigation. The most 

 conspicuous of these is the two Mangsee Islands (Great and Little 

 Mangsee) with their reefs : these lie nine miles north of Banguey, 

 and north and south of each other, extending parallel, two miles 

 east and west, their reefs overlapping, with a passage between, in 

 which there is anchorage, though in deep water. The islands are 

 small, composed of sand, and thickly covered with a luxuriant growth 

 of trees. Between these islands and Banguey, there are two very 

 extensive coral reefs, one, the Helix Reef, lying within 3 miles of 

 Banguey, oval in shape, with a sandy spot bare at low water ; the 

 other, the Cama Reef, triangular in shape, having its longest or hypo- 

 thenuse side to the south, trending east and west 5 miles, while the 

 other two sides trend northeast and northwest from the respective 

 ends, the first a distance of 3, the last of 4 miles : near its centre it has 

 also a bare spot, visible at low water. The distance between the Cama 

 Reef and the Mangsee Islands is 2 miles : its outline is distinctly 

 visible from the islands, and there is usually a ripple on its edges. Due 

 north of the Mangsees, 3 miles, lies the small islet of Salinsingan, resem- 

 bling the Mangsees, though smaller, but without wood. To the 

 east of Salinsingan, and within 3 miles of it, is another island, 

 called Sinanahan. The reef surrounding it is of a curved shape, 5 

 miles in length by li wide; the sand-island on it is Ih miles in 

 length by one-fourth wide : it has scarcely any vegetation on it. 

 Its bearing from the Mangsees is northeast 5 miles. The channel 

 between is 2 miles wide, and free from dangers. Two miles to the 

 north-northeast of Sinanahan lie the Beche de Mer Shoals, occupying 



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