Imagine one unlucky day when you're stranded on a small, uninhabited island among the Riau Islands. Don't be quick to jump up for joy. Don't even dream of setting up a tent, sunbathing on the beach, or frying fresh fish at night. Instead, get right out of that empty island. A big danger may be lurking: the island could be swallowed by the wide-open sea. This can happen because dredgers may be silently sucking the sand from under the island you're on....