HMS Ambush, Britain's most advanced attack submarine has officially joined the Royal Navy fleet.
HMS Ambush is 97 metres long and holds around 100 personnel
The 7,400-tonne sub was commissioned during a ceremony attended by Navy chief Admiral Sir Mark Stanhope at Faslane naval base on the Clyde in Scotland.
The second Astute-class attack submarine was launched in January 2011 at BAE Systems shipyard in Barrow-in-Furness, Cumbria.
The 97-metre Astute-class submarines are designed for coastal and deep sea tasks and are capable of destroying submarines and surface ships.
Since arriving at her home port of HM Naval Base Clyde in September last year the nuclear-powered submarine has undergone extensive sea trials.
HMS Ambush Commanding Officer Peter Green
Ambush holds around 100 personnel and travels at a speed of up to 30 knots.
HMS Ambush Commanding Officer Peter Green said: "The crew are immensely proud to mark the commissioning and to see the culmination of many months of hard work readying HMS Ambush for service with the Royal Navy.
"The crew are looking forward to the challenges ahead and to exploring the full range of the submarine's capabilities before she enters full operational service later this year."
All seven of the Navy's Astute-class vessels will eventually be based on the Clyde.
HMS Ambush travels at a speed of up to 30 knots
HMS Astute entered service in August 2010. The others are named Artful, Audacious and Anson, and two are as yet unnamed.
Admiral Stanhope, known as First Sea Lord and Chief of Naval Staff, said: "These vessels represent the cutting edge of military technology and the future of UK submarine operations for many years to come. The Astute-class vessels will contribute significantly to our mission of protecting the UK's interests worldwide."