By Ed Sawicki
I've been following Iran and their military capabilities since the early 2000s. Sometime in 2012, I commented that although Iran has a military budget that is miniscule compared to the U.S., they spent their money more or less wisely.
Iran knows that if they must go to war with the United States, it will likely involve U.S. aircraft launched from carriers, and not "boots-on-the-ground" troops. If they had some way to threaten the U.S. carriers, it might work to their advantage. Iran now owns three Russian-made Kilo-class diesel-electric submarines, each having six 533mm torpedo tubes. I don't know what weapons Iran has that can be launched from those subs, but possibilities are torpedos, mines, anti-ship cruise missiles, the high-speed VA-111 Shkval rocket torpedo.
Iran also produces its own smaller submarines: the Ghadir-class, and the newer and heavier Fateh-class. The Ghadir subs have two 533mm torpedo tubes, and the Fateh has six.
On April 8, 2015, while using Google Maps to look at Iran's submarine manufacturing facility at Bandar Abbas, I discovered what appeared to be an aircraft carrier in the harbor. It was odd because Iran has never had one. It was also odd because the dimensions of the carrier were smaller than it should have been.
It turns out the Iranians had built a mockup of a U.S. aircraft carrier, complete with mock aircraft on its deck. They used this mock carrier to practice attacks on it after towing it into (or near) the Strait of Hormuz.
Days later, I noticed that the carrier was no longer in the harbor and I couldn't locate it after a lengthy search of the area, including the Strait of Hormuz. Of course, I was using Google Maps, and this is not a near-realtime satellite imaging service. I wish I could afford one.
On April 27, 2015, I noticed that the carrier was back in the harbor and looked like it had been attacked. The decking was raised as if an explosion had occurred below decks. Plus, all the "aircraft" on deck are gone.
Later press reports indicated that the Iranian "carrier" was towed to waters near the Strait of Hormuz and attacked by Iranian surface craft. Iran named their carrier the Target Barge because it was a barge made to look like a U.S. Nimitz-class carrier.
It was attacked by"swarms" of high-speed boats firing 107-millimeter rockets and Noor anti-ship cruise missiles.
Sources
Wikipedia: Ghadir-class submarine
Wikipedia: Fateh-class submarine
Wikipedia: Islamic Revolutionary Guard Corps Navy
Wikipedia: Type 63 multiple rocket launcher
Wikipedia: Taregh-class speedboat
Reddit: Iran's IRGC Navy has just received an additional 340 new fast-attack boats of various types