The waters around the coast are some of the clearest in the world and the depths are filled with amazing coral and many species of fish and other marine creatures.
The depths of the waters are brimming with fish and coral. 
mnli hypothesis: The depths of the waters are brimming with fish and coral.  premise: The waters around the coast are some of the clearest in the world and the depths are filled with amazing coral and many species of fish and other marine creatures.