Note 50 — Chapter VIII · THE BUILDING OF REEFS

Owing to the practical absence of tide in the Red Sea the boat channels of the fringing reef are discontinuous, so that at intervals the canoe men must wait for favourable weather and put out to the open sea. In Zanzibar, e.g., one can travel the whole 60 miles of the east coast within the reef but for the crossing of one bay, except at lowest spring tides. Some of the deeper parts of the boat channel of Red Sea reefs are due to faulting (see next chapter) as may be also a very peculiar reef channel just north of Mombasa Harbour.