Even though ocean mapping scientists working in tropical Australian waters are mainly interested in the deeper seafloor, it is useful to view shallow coral reefs to help understand reef growth patterns. When seen from the air, coral reefs show a huge variety of shapes and growth forms. Ocean mapping scientists can then try to relate these shapes to similar undersea features, such as the drowned or submerged reefs that are found in deeper parts of the Great Barrier Reef. These images show a variety of coral reefs and sand cays found on the northern Great Barrier Reef of Australia.