The submarine was put into service with the Royal Navy in 1963 and served there in the First U-Boat Squadron.
The Otus was used during the Falklands War and in the Persian Gulf . After 28 years of service, the Otus was decommissioned in 1991. The boat was later bought by a German entrepreneur. After being transferred to Germany, it was overhauled outboard in the Stralsund shipyard and given a new coat of paint in the original color. Since then, the Otus can be viewed as the “ U-Boat Adventure World” in the Sassnitz city harbor.