20,000 colleagues under the sea

摘要

Sailing the seven seas is old hat. The latest trick is to glide them. Sea gliders are small unmanned vessels which are now cruising the briny by the hundred. They use a minuscule amount of power, so they can stay out for months. And, being submarines, they are rarely troubled by the vicissitudes of weather at the surface. Their only known enemies are sharks (several have come back covered in tooth marks) and fishing nets.