Los Angeles-class fast attack submarine USS Hartford (SSN 768) and Seawolfclass fast attack submarine, USS Connecticut (SSN 22) both surfaced within the Arctic Circle on 10 March 10 during the multinational maritime Ice Exercise (ICEX) 2018 north of Alaska. Both fast-attack submarines as well as HMS Trenchant (S91), are participating in the biennial exercise in the Arctic to train and validate warfighting capabilities of submarines in extreme cold-water conditions. ICEX provides the US Submarine Force and partners from the Royal Navy an opportunity to test combat and weapons, sonar, communications and navigation systems in a challenging operational environment. Furthermore, the unique acoustic undersea environment is further compounded by the presence of a contoured, reflective ice canopy when submerged.