112 



HYDROGRAPHY. 



The island is almost divided into two parts or peninsulas ; the 

 largest, Tahiti, is 90 miles in circumference and nearly circular : it 

 lies to the west ; the smaller one, known by the name of Taiarabu, 

 is of oblong shape and about 30 miles in circumference : they are both 

 mountainous, and rise in lofty and sharp ridges, Tahiti, next to 

 Hawaii, being the highest island in the Pacific, — the altitude of 

 Pitohiti and Orohena being between 9,000 and 10,000 feet. It is 

 volcanic, and surrounded by an extensive coral-reef. In clear weather 

 it may be seen at the distance of 50 miles ; but ordinarily the highest 

 peaks are hidden by clouds, when it is not visible over half that dis- 

 tance. 



Tahiti is indebted for its fine harbors to the coral reefs, and only 

 where these are detached from the shore are they found. The south 

 side has no harbors, the reef being in some places wanting, while in 

 others it is attached to the shore. On the north, however, the har- 

 bors are continuous, viz., Matavai, Papaoa, Toanoa, and Papeiti, 

 extending from Point Venus to the west 8 miles. There are other 

 harbors, on the east and southwest sides, but they are more or less 

 exposed to the influence of the easterly and southwesterly winds ; 

 those on the northwest and west sides, with the exception of Matavai 

 Bay, are at all seasons quite secure. 



Matavai Bay is protected to the north and east by Point Venus 

 and the projecting reefs off it, as well as somewhat by the Dolphin 

 Bank to the northwest. With the trade winds it is a convenient har- 

 bor for a vessel to seek, as there is no difficulty whatever in entering 

 or departing from it. The least depth of water found on the Dolphin 

 Shoal was 13 feet 6 inches. It may be passed on either side ; if to the 

 eastward, the reef ought to be kept close aboard and a lookout from 

 aloft ; intending to anchor, it is better to turn short around the reef 

 and pass through this passage, as a vessel thereby avoids any necessity 

 of beating up. The bay is entirely clear, with the exception of two 

 small shoals lying to the north of One Tree Hill, on which there is not 

 over 3£ fathoms water : the depth in the bay varies from 6 to 18 

 fathoms. The anchorage is good in any part of the bay, but it is 

 better to anchor well up towards Point Venus ; the bottom black sand 

 with mud. 



Water is to be had without difficulty from the river that empties 

 behind Point Venus, and can be obtained by passing over the sand- 

 beach, where the stream has the appearance of having formerly 



