 Like all Royal Navy submarines, the "Trafalgar" class have strengthened fins and retractable hydroplanes, allowing them to surface through thick ice.Four boats of the class — "Torbay", "Trenchant", "Talent" and "Triumph" — have been fitted with the Sonar 2076 system, which Thales describes as having a ""reputation as the world’s most advanced, fully integrated, passive/active search and attack sonar suite"".Beginning in 2014, the last four boats of the class underwent a communications package upgrade.