This is a good visualization: http://www.bluehabitats.org/wp-content/uploads/2015/04/Screen-Shot-2015-04-30-at-12.22.44.png http://www.bluehabitats.org/wp-conte

This is a good visualization: http://www.bluehabitats.org/wp-content/uploads/2015/04/Screen-Shot-2015-04-30-at-12.22.44.png http://www.bluehabitats.org/wp-content/uploads/2015/04/Scree... The continental shelf is quite flat. The reef follows exactly along the rim of the shelf. I believe the coast used to extend all the way to where the reef now ends. The reef started growing as this part was slowly submerged in shallow water. Coral reefs only build in the photic zome (<50m) since they (specifically, the algae which produce the nutrients that coral polyps live on) require photosynthesis.