HMS Otus was a British submarine launched in 1956 and served in the Royal Navy until 1991. It was part of the Oberon-class submarines, designed for anti-submarine warfare and intelligence gathering. The vessel was notable for its advanced sonar systems and ability to operate stealthily underwater. After decommissioning, HMS Otus was preserved as a museum ship in Birkenhead, England. Visitors can explore its interior and learn about life aboard a submarine during the Cold War era. The submarine serves as an educational resource, showcasing naval history and technology.