The Royal Navy's newest nuclear submarine has set sail to begin sea trials on Saturday.
The second Astute class submarine, Ambush, set sail from BAE Systems in Barrow-in-Furness, Cumbria, on Saturday morning.
The 7,400 tonne attack submarine left the site for Her Majesty's Naval Base (HMNB) Clyde, Faslane, which will become its operational base.
This major milestone in the submarine programme is the point at which Ambush will begin to test its range of capabilities, under the control of Ambush Commanding Officer, Commander Peter Green and his crew.
Ambush is the second in a planned class of seven submarines and she follows sister vessel HMS Astute to HMNB Clyde, in Scotland, where the first in class has been based since leaving BAE Systems in 2009.
Minister for Defence, Equipment, Support and Technology Philip Dunne said: "Ambush and her sisters are the most powerful and advanced attack submarines ever ordered for the Royal Navy, they are needed by the fleet and they will play a vital role in the future defence of the UK. The completion of Ambush is a tribute to the hard work and commitment of the thousands of people employed in this country's world-class submarine industry."
The Astute class boasts a range of capabilities inside each 97 metre long hull. Powered by a Rolls-Royce nuclear propulsion system, the reactor never needs refuelling.
The sonar system has the processing power of 2,000 laptops and can track ships 3,000 miles away. They are armed with both Tomahawk land attack missiles and Spearfish torpedoes and her missiles have a target range of 1,200 miles with accuracy measured in metres.