Photo credit: Repoort / CC BY 2.0 The oceans are afloat with boats, buoys, and ships. But scientists are sending another kind of sea-craft afloat in the great blue: robots. A variety of ocean-going robotic devices are setting sail to help monitor sharks and rebuild coral reefs. Tracking great white sharks This high-tech surfboard is cruising the waves along California's Pacific coast, a famous hotspot for great white sharks. Marine biologist Barbara Block of Stanford studies oceanic predators like great whites by tagging them with acoustic tags that emit a signature sound. These sounds are picked up by stationary sensors when a shark swims within 1,000 feet, allowing scientists to track its movement. Block has tagged 120 great whites and a several other shark species. Three stationary buoys pick up sounds from the acoustic tags, but the robot, called the Wave Glider, cruises the ocean to reach waters outside the range of the buoys. This first Wave Glider is called the Carey, after...