3G0 



HYDROGRAPHY. 



The channel to the west of Tawitawi, between it and Borneo, is also 

 safe, but during the season of the northeast monsoon, the current sets 

 with strength through it to the southward. If this channel should be 

 attempted, care must be taken not to approach too near to the Pearl 

 Bank, with its islets and shoals, which extend some distance around it. 



The Island of Tawitawi is reported as having two extensive lakes, 

 one of which is said to communicate with the sea, having at high 

 water a channel of from 4 to 6 fathoms leading into it. The average 

 depth of the lake is reported to be 8 fathoms. The channels among 

 the small islands are shallow, and in places very narrow : this locality 

 is considered the best pearl fishery of this archipelago, and is frequented 

 at all seasons. 



The small group of islands, lying to the northwest of Sooloo, and 

 distant 20 miles, of which Pangootaran is the largest, are all low, 

 with deep water between them : some have projecting coral reefs, but 

 they may be easily avoided : it is better not to attempt to pass be- 

 tween them without daylight. They occupy an area of 40 miles in 

 length by 12 miles in width. 



The smaller islands between Basillan and Sooloo are very numer- 

 ous, and cover almost the entire space : they all appear to be accurately 

 laid down ; many were ascertained to be so by numerous cross bearings 

 and angles, and I feel confidence in stating that, from my examina- 

 tion, our charts may be relied on. Most of the islands are high, and 

 may be closely approached. 



In passing through the Sooloo Sea, either to the east or west, the 

 Island of Cagayan Sooloo, and the small islets near it, should be 

 sighted : their position in latitude and longitude is well determined. 

 Cagayan is moderately high and may be seen a considerable distance. 

 I think it advisable for navigators to p.ass near it : its bearings from 

 time to time may show the effect of the current. It is 5 miles long, 

 east and west, by 3 miles wide. Several small islets lie off to the 

 northward ; the most northern one is Kanaposan. 



Between Cagayan Sooloo and the Straits of Balabac, there are 

 several coral-banks, on which an anchor may be dropped in 25 or 30 

 fathoms : they range east and west for a distance of 40 miles. The 

 Vincennes anchored on Midnight Shoal : it is about half way between 

 Cagayan Sooloo and the Straits of Balabac. 



