This week, The Economist released an article referencing the use of robots in the field of oceanography, citing the Rutgers University Department of Marine and Coastal Sciences' use of the Slocum Electric Gliders.  The following is an exerpt from the article which can be found here: http://www.economist.com/node/21556551

Exploring the Oceans: 20,000 colleagues under the sea

Fleets of robot submarines will change oceanography

Image by Dave Simonds from http://www.economist.com/node/21556551

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. 

Sea gliders are propelled by buoyancy engines. These are devices that pump oil in and out of an external bladder which, because it deflates when it is empty, means that the craft's density changes as well. This causes the glider to ascend or sink accordingly, but because it has wings some of that vertical force is translated into horizontal movement. Such movement is slow (the top speed of most gliders is about half a knot), but the process is extremely efficient. That means gliders can be sent on long missions. In 2009, for example, a glider called Scarlet Knight, operated by Rutgers University, in New Jersey, crossed the Atlantic on a single battery charge, though it took seven months to do so...

For the full article, continue to The Economist