Modern understanding of coral reefs begins in Charles Darwin's book, On the Structure and Distribution of Coral Reefs. In this classic book written in 1842, he distinguished three main types of reefs: the fringing reef, the barrier reef and the atoll. The fringing reef is found close to shore and essentially follows the shoreline profile. Its stony corals need a firm base on which to settle and must compete with many other sedimentary organisms in search of a firm substrate on which to settle. In offshore waters, this substrate is generally provided by limestone secreted by earlier hard corals on the (often volcanic) rock. However, if there is a firm rock base, as in fringing reefs, sedentary rivals can establish themselves in large numbers without waiting for reef-building corals to lay the foundation (Stafford-Deitsch 20). Thus, stony corals do not necessarily have to be the main constituents of the reef. Sponges, soft corals and corraline algae are abundant throughout the fringing reef. Some of the most beautiful fringing reefs in the world are found along the edges of the Red Sea, where conditions are ideal for reef growth. The water is surrounded by a desert. Therefore, there is virtually no rain to wash sand or fresh water into the sea. Additionally, there are very few clouds in the area allowing sunlight to reach the surface, resulting in much warmer water than one might expect at this latitude. The reefs of the Red Sea are among the richest and most diverse. If one were to swim above the crest (the edge of open water), one might panic as the reef drops dramatically to unknown depths. This way, wave action is not allowed to stir up a lot of sediment, which would damage the reef, because the sediment is deposited below the reach of the waves. Little sediment at the top of the reef makes the water clear, maximizing the amount of sunlight that reaches the reef (Stafford-Deitsch 21). The second type of reef according to Darwin is the coral reef. It differs from the fringing reef in one main respect: the area between the living coral of a fringing reef and the shore is the reef flat, but the area between the coral reef and the shore is a lagoon (Stafford-Deitsch 21 ). The lagoon is a relatively shallow area of ​​water, only a few meters