HMS Ambush is an Astute-class nuclear fleet submarine of the Royal Navy, the second boat of her class. Ambush is the third vessel, and the second submarine, to bear the name in Royal Naval service. She was ordered in 1997, laid down in 2003 and commissioned in 2013.
Ambush's nuclear reactor will not need to be refuelled during the boat's 25-year service. Since the submarine can purify water and air, she will be able to circumnavigate the planet without resurfacing. The main limit is that the submarine will only be able to carry three months' supply of food for 98 officers and ratings.
Ambush has provision for up-to 38 weapons in six 21-inch (533 mm) torpedo tubes. The submarine is capable of using Tomahawk Block IV land-attack missiles with a range of 1,000 miles (1,600 kilometres) and Spearfish heavyweight torpedoes.
Ambush was ordered from GEC's Marconi Marine (now BAE Systems Submarine Solutions) on 17 March 1997. She was laid down at Barrow-in-Furness on 22 October 2003, officially named on 16 December 2010, launched on 6 January 2011, completed her initial dive test on 30 September 2011, and departed Barrow for sea trials on 15 September 2012. Ambush was commissioned in a ceremony at HM Naval Base Clyde on 1 March 2013.