DOCUMENTARY PREMIERE: This documentary is commendably aggressive in its approach. It shows the majestic beauty, color and variety of coral reefs around the world – then shows ones that are dead or dying, in a compare-and-contrast exercise that is little short of mortifying. But rather than be all doom and gloom, Chasing Coral suggests what can be done next – especially by young people willing to help, in both documenting and improving those crucial undersea worlds.