Onyx was a Diesel Electric Sub which was used for inserting SF on to the Falklands. She was also used for Elint gathering.

The OBERON class was a follow-on to the earlier PORPOISE class, and they appeared almost identical. New hull materials gave a deeper diving depth, and additional soundproofing was provided. These submarines were very quiet for their day, and stayed in service with various Navies past the year 2000. At the time, they were state of the art conventional subs, despite being based on a late-WWII German hull design. They were originally fitted with two stern-facing 'short' torpedo tubes, but the advent of reliable guided torpedos made these obsolete. The stern tubes were then either used for beer storage for the crew, or were eventually converted for other uses (the Canadian Navy used this space for the installation of a towed array sonar). The final member of this class, HMS ONYX, was the only conventional submarine to see service in the Falkland's War of 1982, where she was used for special operations in and around the islands. The last of the O-boats in RN service were paid off during the 1990s. ONYX is now a museum piece in Birkenhead (near Liverpool), and OCELOT is part of a museum in Chatham.
My bold, so the Canucks use it for a sonar and the Brits use it for beer!!! Which boat would you want to be on?