This is a potentially important advancement in technology with many uses, inculding scientific, defensive and and commercial aspects:

Excerpts from: http://www.economist.com/node/21556551


Exploring the oceans
20,000 colleagues under the sea
Fleets of robot submarines will change oceanography
Jun 9th 2012 | from the print edition


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. .................

Broadly speaking, these machines have three sorts of application: scientific, military and commercial.

At the moment, science rules the roost. For cash-strapped oceanographers, gliders are a blessing. Their running costs are negligible and, though buying one can cost as much as $150,000, that sum would purchase a mere three days of, say, a manned trip to the Southern Ocean.

Gliders, moreover, give a continuous view of what is going on, rather than the series of snapshots yielded by equipment lowered from a vessel at the surface. Besides tracking pollution, watching volcanoes and measuring icebergs, they are following fish around, monitoring changing temperatures in different layers of seawater and mapping the abundance of algae. ..............

Military applications are growing, too. America’s navy, for example, has ordered 150 gliders from Teledyne Webb’s sister company, Teledyne Brown, for what it calls its Littoral Battlespace Sensing-Glider programme. To start with, these gliders will be used individually, to measure underwater conditions that affect things like sonar. Eventually, the plan is to link them into a network that moves around in a co-ordinated manner.

Gliders are also ideal for gathering intelligence. Having no propellers and no engine noise, they are difficult to detect. They can be delivered by submarine, and can lurk unseen for as long as is necessary. Any shipping, whether on the surface or under it, which passes near a glider can be detected, identified and pinpointed without it realising it has been spotted. Indeed, the American navy is now evaluating a design called the Waveglider, made by Liquid Robotics of Sunnyvale, California, for submarine-detection work.

The third use, commerce, seems, at the moment, to be the smallest—though that may be because the companies involved are keeping quiet about what they are doing. But Joe Dyer, the chief strategy officer at iRobot, thinks oil-and-gas exploration will be a big market for the firm’s gliders, because they can survey large areas of seabed in detail at low cost.

..................

Dr Arima’s greatest interest, though, is like America’s navy’s: that his gliders should collaborate. His plan is to deploy 1,000 of them in a network that surveys and measures the oceans. If it works, the single spies of sea-gliding really will have become battalions, and the ocean’s fish will find themselves shadowed by shoals of mechanical counterparts.