Diving on the outside on an atoll has a few positives. Very clear and warm water, an ocean floor like the side of a conical volcano.
Charles Darwin first stated that he believed an atoll was a submerged volcano slowly sinking with growing corals keeping pace with the sinking. What would then happen if the corals ceased growing, as per \global warming\ and other issues such as \rising sea levels\?
The islands might begin to wash away. The people would need new homes provided elsewhere. All much the same as it once was when the coral eating starfish (\Acanthaster planci\) were first noticed on coral reefs in the Pacific Ocean and then elsewhere.