Coral reefs—those things that shape some of surfing’s most previous platforms—are in as existential a crisis as ever, perhaps with no thanks in particular to us humanoids. Yada, yada, yada, the metamessage the environmentalists take redundant care in delivering. But that’s a dour note for another entry into this vast compendium of nautical intrigue.  Today, a positive spin whirs across our desktops: Not all coral reefs the world over are doomed to succumb to the pesky rash of marine heat waves that just doesn’t seem to abate. Thanks to hidden ocean currents, select reef habitats, such as a nameless one in the Andaman Sea in the northeastern Indian Ocean, get regular-enough infusions of cool, clear water when and where climate conditions dictate.…