HAO. 113 



we could see the southeast face of Ravahere to be one string of islands 

 (PI. 70, fig. 2) as far as the eye could distinguish. In addition to the 

 secondary lagoon parallel to the west shore the lagoon at the south end is 

 divided by a flat into two lagoons, a little more to the northward than is 

 marked on Wilkes's chart. Such a division is not uncommon in some of the 

 Paumotu atolls. We have found such a division by reef flats into secondary 

 lagoons in Anaa and Tahanea. At the north end of Ravahere a wide flat 

 runs from the west coast far into the lagoon, on the inner edge of which 

 rises an island witli high shingle beaches, as on the islands on the east face of 

 the northern horn. The outer reef flat on the south shore is covered with 

 coral rubble, and on the sea face of the west flat large boulders line the 

 outer edge of the reef flat. Ravahere at the northern extremity is very 

 narrow, and only a thin line of dark blue water indicates the small extent of 

 deeper water in the lagoon, which is said to be very unequal in depth, and 

 full of deep holes. 



Hao- 



Plates 67, 201, 203; 205, fig. 2. 



Hao was discovered by Bougainville. It is thirty miles long and about five 

 miles wide.^ It is shaped somewhat like a boomerang ; the southern part 

 of the atoll turning ofE to the eastward at an angle from the general trend, 

 as is the case with Tahanea, Rangiroa, and Makemo. Two sinks are 

 indicated on the sketch of the entrance to Hao." They have probably been 

 formed in the same manner as those near the passes of Rangiroa, Makemo, and 

 the like. It is well wooded on the weather side, the islands and islets of the 

 lee side are generally bare, and the sea pours over into the lagoon through the 

 gaps between the islands. The entrance of this lagoon is on the northern side, 

 the tide running in and out with such velocity as to make numerous over- 

 falls. The depth of the lagoon of Hao, especially at the northern extremity, 

 is as great as 30 fathoms in places, although the average depth is about 15 

 to 20 fathoms. The northern part, but specially the southern and eastern 

 parts of the lagoon are studded with coral knolls and coral patches, which 

 make navigation extremely dangerous. 



' A. Chart 1111. ^ n^ij. 



