The Russian Shkval torpedo was tested for Iranian naval officials in 2004 and the resulting data were described in several newly disclosed Persian-language documents.

Iran’s own Hoot torpedo is evidently derived from the Shkval.  Both are high-speed, supercavitating anti-ship missiles.

Some of the newly disclosed Iranian documents, which include Shkval technical specifications and test performance data as well as Hoot production records, are marked “khayli mahramaneh” or “very confidential,” the third of four classification levels used in Iran.  The documents have not been approved for public release, but copies were obtained by Secrecy News.