WATCH: Fourth Astute Class Submarine Completes First Dive Posted by Michael Brash | Jan 18, 2018 | Defence, Defence and Military Affairs, Latest News | 0 | > BAE Systems’ fourth Astute class submarine, Audacious, has completed her first ever dive at the company’s site in Barrow-in-Furness. Watch as the 7,400 tonne, 97-metre long attack submarine submerges beneath the water.