362 



HYDROGRAPHY. 



an area of 10 miles north and south, by 4 miles wide : they have 

 several small sand-banks bare at low water, and a depth of 20 to 25 

 fathoms near them on the east and west sides. To the west of the 

 most northern part of these shoals, lies Turtle Shoal, nearly circular, 

 3 h miles in diameter: there is also a sand-bank on it, visible at low 

 water. The small Island of Lamboogan lies 5 miles farther to the 

 north, and due east of the south point of Balabac 10 miles : it is sur- 

 rounded by an extensive coral reef, which projects a mile to the 

 east, and 2 miles from its west point to the southwest. Landalaman 

 Islet lies 5 miles to the north of Lamboogan. 



The only remaining danger is Sandy Isle, winch lies off to the west, 

 on a bearing of south 66° west, 20 miles from the south end of Balabac, 

 and north 45° west, 65 miles from Point Seeaggoot, the north point 

 of Balambangan. The range of the Monmouth Isles, on with the 

 Peak of Banguey, will strike it. Throughout these straits the sound- 

 ings range from 25 to 40 fathoms. I conceive there is little need of 

 anxiety on the part of the navigator in approaching and passing 

 through these straits : there is ample room for turning to windward if 

 the wind should not permit a direct course through, and if night ap- 

 proaches or calms should ensue, an anchor or kedge may be dropped, 

 to await the breeze or the turn of the tide. It is high water, full and 

 change, at the Mangsee Islands, at lOh. 30m. a.m. : the tide rises and 

 falls 9 feet. 



The route in passing in or out through the straits, must be left 

 optional to the navigator, but I should prefer the southern one, 

 towards the Mangsee Islands. All the shoals maybe closely approached, 

 and their outline will be quite visible from aloft. It is my impression 

 that the wind will prove generally favorable to pass either way, and 

 that but a few hours will suffice to place a vessel beyond all danger, 

 either of accident or delay. The great preference the route through 

 the Sooloo Sea has over the other routes is, that whilst it is free from 

 the calms and currents of the Macassar Straits, it likewise avoids the 

 necessity of encountering the dangerous shoals and strong winds of the 

 Palawan Passage, in the contrary monsoons, both causing great anxiety 

 to the navigator, and wear and tear to the vessel ; besides, there is no 

 route so short or direct towards the new Equatorial Passage to the East 

 in the Pacific Ocean. The reefs are bare at low water. Most of the 

 time at our anchorage between the Mangsee Islands, we experienced 

 little or no current, but twelve hours before the moon changed, it ran to 



