138 THE CORAL REEFS OF THE MALDIVES. 



Although several of the p.asses into Suvadiva are shallow/ south of Madu 

 we have only six fathoms in the channel, south of Diaddu and of Kandu 

 Huludu, seven, yet the greater number are wide and deep, admitting free 

 access to the outside sea, so as to make Suvadiva a strictly oceanic atoll, 

 if I may so call open atolls of great depth like Suvadiva. Suvadiva has a 

 greatest depth of forty-nine fathoms, with the majority of the soundings 

 near forty fathoms. It is by far the largest body of deep water in the 

 Maldives; and though it contains at least two hundred islands and banks, 

 they are quite lost in this huge atoll, and so far apart that one often 

 seems to be steaming at sea or through an archipelago of small distant 

 islands, or making for the outer rim of a neighboring atoll, as when passing 

 from the face of one group to another. The dark color of the deep enclosed 

 waters adds to the deception. 



Many bays are to be seen on the sea face of the larger islands on the 

 eastern side of Suvadiva, plainly showing that the larger islands have been 

 formed by the coalescence of smaller ones, joined at first, perhaps, merely 

 by a shingle bar, or a line of coral boulders or of sand-bars. With the 

 accumulation of material the connecting belt of shingle becomes a string 

 of banks or of islets, till finally the outer extremities of adjoining islands 

 are united, and a shallow sheet of water is enclosed within three sides of a 

 rectangle. The open lagoon face in its turn is barred in the same way by 

 chains of sand-bars or islets ; they, in their turn, become united, and thus a 

 closed, shallow lagoon is formed. The long island of Huluwarolu is only in 

 a more advanced state of coalescence than the smaller and still indepen- 

 dent islands and islets to the south of it. On the west face of Suvadiva 

 a similar process has been going on, but the islands are more disconnected 

 than on the east face. Only a few larger islands have been formed on the 

 reef flats of the western face, such as Havaru, Kandudu, Hondedu, and Nadale. 

 The western reef flats are edged with numerous small islands and islets, until 

 we reach the large islands on the southern reef flats of Suvadiva, like Fiori 

 and Matoda, all composite islands, like those of the east face. 



^ In a number of the passes of the central Maldives, the outer soundings on the rim are shallower 

 than those on the inner faces ; they indicate the submarine extension of the crest of the adjoining reef 

 flats, and are well within the depths at which corals may grow. 



The same is the case in a few of the passes of the northern Maldives, the northern passes of 

 Haddummati, and many of the passes on the faces of Suvadiva and of Addu. 



