Drone sub chaser
The US Navy has begun testing a radical 'drone boat' that will automatically scour the seas for enemy submarines for months at a time.

The Navy hopes the 'sea hunter' will end the growing threat of quiet, diesel powered enemy submarines entering American waters undetected.

Today they revealed footage of the 132 foot long ship, officially named 'The Anti-Submarine Warfare Continuous Trail Unmanned Vessel' in its first high speed tests.

The ACTUV technology demonstration vessel was tested in Portland, where it reached a top speed of 27 knots (31 mph/50 kph).

The vessel is scheduled to be christened on April 7, 2016, with open-water testing planned to begin in summer 2016 off the California coast.

Darpa director Dr. Arati Prabhakar and deputy director Dr. Steve Walker revealed the craft earlier this year. 'Imagine an unmanned surface vessel following all the laws of the sea on its own,' Walker told media, 'and operating with manned surface and unmanned underwater vehicles.'

The robot boats will go to sea for us to three months at a time.

It will be christened in April in Portland, Oregon, and then begin to demonstrate its long-range capabilities over 18 months in cooperation with the Office of Naval Research and the Space and Naval Systems Warfare Command.

'We think the real cost savings will be in operating this vessel at sea compared to how we operate vessels today,' he added. 'It could be used for counter-mine missions, reconnaissance and resupply.'

The project began in 2010, when the Defense Advanced Research Projects Agency, or DARPA, announced that they were building a 132-foot autonomous boat to track quiet, diesel-powered submarines.

The program was dubbed Anti-submarine Warfare Continuous Trail Unmanned Vessel, or ACTUV.

In six weeks of tests along a 35-nautical mile stretch of water off of Mississippi earlier this year, testers at engineering company Leidos and Darpa put the ACTUV's systems through 100 different scenarios.

The test boat was able to tail a target boat at 1 kilometer's distance, something military bosses say is a  major step forward.

 'Picking up the quiet hum of a battery-powered, diesel-electric submarine in busy coastal waters is 'like trying to identify the sound of a single car engine in the din of a major city,' says Rear Admiral Frank Drennan, commander of the Naval Mine and Anti-Submarine Warfare Command.

Speaking at a National Defense Association Event in Virginia last year, Darpa program manager Ellison Urban outlined why the Navy needs sub-hunting boat bots.

'Instead of chasing down these submarines and trying to keep track of them with expensive nuclear powered-submarines, which is the way we do it now, we want to try and build this at significantly reduced cost. 'It will be able to transit by itself across thousands of kilometers of ocean and it can deploy for months at a time.  'It can go out, find a diesel-electric submarine and just ping on it,' said Urban.

Diesel-electric submarines have nearly-noiseless engines, are incredibly difficult to track from afar.Price tags ranging from $200-$300 million put diesel-electric subs within reach of smaller, volatile countries.

Russia has been selling diesel-electric subs to buoy its shipyards, triggering what some are calling an undersea arms race.

Reportedly, Algeria has ordered two, Venezuela is expecting five, and Indonesia will have six subs by 2020. Iran claims to have a fleet of 17 diesel-electric subs.

To spot the threat, Leidos developed an unarmed, unmanned vessel to shadow diesel-electric subs for months across thousands of miles of ocean and chase them out of strategic waters.

'Called the ACTUV, the unmanned boat can be deployed for months and track underwater threats for thousands of miles without human contact.

'It keeps our troops out of harm's way and also minimizes risks to the marine ecosystem by limiting the use of sonar,' the firm says.

It claims diesel-electric submarines are quickly becoming one of the biggest threats to naval operations and a $1.8 trillion commercial shipping industry.

'Detecting and tracking these stealthy subs presents a huge challenge even for the U.S. Navy, the world's most technologically advanced fleet.'

Source: dailymail.co.uk