There is something wonderful and sad about the Catlin Seaview Survey. Its aim is to document in stunning detail the great coral reefs of the world, using special high-resolution, 360-degree panorama cameras. Think Google Street View, submerged. (Indeed, Google is one of the survey sponsors.) The work began only a year ago, but already a visit to the survey website gives you a taste of what’s to come. You can go on virtual dives from Australia to Belize, and the experience is about as close to the thrill of scuba exploration as you can have without getting wet. That’s the wonderful part. But the survey’s deeper purpose, as it were, is to create a record of vast natural wonders that are fast disappearing. Over the past 50 years the world has lost about 40 percent of its coral reefs, killed off by destructive fishing, pollution, and climate change. The sponsors of the survey claim that as this decimation of the reefs continues—and it will—it will have a major impact on the lives of some 500 million people who rely on these fragile habitats for food, tourism income, and coastal protection. That’s the sad, even tragic part.