In Iran, the IRGC (Islamic Revolution Guard Corps) has its own “Navy of the Army of the Guardians of the Islamic Revolution”. The main job of the IRGC is to protect the religious dictatorship from the Iranian armed forces and a growing number of angry Iranians. As a result, the IRGC Navy has about as many personnel 23,000), including marines and naval aviation as the Iranian Navy. Th IRGC force has about 40 large missile and torpedo boats (100-200 tons each) and over a thousand smaller craft, many of them just speedboats with dual outboard engines and machine-gun mounts.
Now the IRGC Navy has been extending its reach by building oil tankers for sale to foreign customers. The IRGC owns a growing number of commercial firms and is increasingly accused of using market manipulation and intimidation to take sales from commercial firms. The IRGC has seized or stolen billions of dollars in assets over the last few decades and the profits from these firms are used to finance many of their overseas terrorism projects. The two IRGC built tankers produced so far are Aframax class ships, meaning they have a deadweight tonnage of 80,000 to 120,000 tons and carry up to 750,000 barrels of oil. Earlier the IRGC had converted several cargo ships to “warships” by arming them and installing a platform for a helicopter. At the same time the IRGC keeps building more smaller armed ships and boats.
The more numerous small craft are technically warships but are largely used for intimidation, harassment and sometimes seizing foreign ships. One example was the seizure of a South Korean chemical tanker in early January 2021. This was part of an effort to force South Korea to release $7 billion in Iranian assets frozen by economic sanctions. The IRGC insists they did not hijack this tanker but seized it for violating pollution laws. The IRGC usually comes up with a phony excuse like that to avoid being tagged as hijackers. The tanker is still be held by the IRGC and guarded by IRGC gunmen. South Korea immediately sent some warships to where the tanker is being held and and tried negotiations to get the tanker released. Negotiations failed so South Korea is seeking help from other Gulf oil states, pointing out letting this Iranian bad behavior go unpunished can increase insurance rates and appear to prove that Iran can do whatever it wants with no consequences.
For actual wartime use or for seizing foreign ships, up to a dozen “revolutionary guardsmen” will be found on these small boats, armed with assault rifles, machine-guns, and RPGs. Some boats are equipped as suicide bomb craft and only carry a crew of two or three, plus half a ton or more of explosives. Some of these craft have been seen with anti-tank missiles. The “Guardian Navy” also has a few helicopters and several thousand “marines.” Its small boats spend a lot of time at sea, mainly patrolling the 2,800-kilometer-long coastline. This includes 740 kilometers in the Caspian Sea. The most active coastline is in the Persian Gulf but the IRGC mission is to keep an eye on the entire country, especially the regular military and any new threats or opportunities. As a result, these small boats wear out quickly and new ones are constantly being delivered, often in large batches. That is usually turned into a media event. The IRGC is a major practitioner of Information War (militarized public relations.)
The IRGC builds its own small boats and regularly holds highly publicized ceremonies to induct new boats into the IRGC Navy. The most recent such event was held in May 2020 for 112 new armed speedboats. Most of these were Zolfaqar, Heidar and Meead type boats. The Zolfaqar is a speedboat with a top speed of 120 kilometers an hour and capable of carrying two Nast 1 anti-ship missiles. It is unclear how effective these 350 kg (550 pound) missiles are when fired from a fast-moving 16.3-meter (52 foot) Zolfaqar. The rocket propelled Nasr 1 has a range of 35 kilometers and uses a small radar in the nose to detect and home in on the largest ship it encounters. In clear weather, the crew of a Zolfaqar could spot the superstructure of a warship or large commercial ship up to 15 kilometers away. Then you turn the boat towards it, fire a Nasr 1 and hope for the best. It would take less than a minute for the missile to reach the target. A warship, if its defensive systems were turned on, could probably destroy or mislead (jam the radar) of the missile. A commercial vessel, like a tanker or cargo ship would probably get hit. If a tanker were loaded, the missile would probably start a fire if the hull was hit. If the superstructure was hit the 100 kg (220 pounds) of explosives in the warhead would do a lot of damage but not sink the ship and would probably not even stop it. Large commercial ships have proved quite capable of taking a missile hit and keep going. While Zolfaqars can haul two 350 kg Nasr 1 missiles, none have been seen firing them and hitting a distant target. Nasr 1 is meant for use from larger surface ships, shore batteries (fired from a truck) or launched from a helicopter.
Zolfaqar is one of two Iranian speedboats based on the British Bladerunner fast boat, one of the fastest in the world. Normally Zolfaqar is only armed with two 12.7mm machine-guns and smaller rocket launchers. Iran smuggled in a 16-ton Bladerunner 51 in 2010 and has since manufactured dozens of Seraj 1 and Zolfaqar versions of it.
Most of the IRGC speed boats are smaller and armed with machine-guns and small rockets. Some will be loaded with explosives and used as manned or unmanned suicide boats. Iran has had some success with unmanned suicide boats in the Red Sea, where they supply Yemeni Shia rebels with large rockets and the tech to produce remotely controlled suicide boats locally.
The IRGC operates most of the 1,500 small boats used by the IRGC seagoing forces and the regular navy. Because of this, the U.S. Navy has had to develop two sets of tactics for dealing with Iranian naval forces. Iran’s two navies are very different from each other. The traditional navy exists alongside the less well equipped, but more fanatical, forces of the IRGC. Both forces are equipped, trained, and led very differently.
The Iranian Navy has had little access to foreign shipbuilders since the 1980s, but recently become capable of building their own warships. These are crude but they float and their weapons generally work. These surface ships are small craft (1,500-ton corvettes and 2,200-ton frigates) while the submarines are largely of the miniature variety. There are only a few of each and construction is proceeding slowly so that, apparently, mistakes in the previous one can be discovered and fixed. Currently, the only major surface warships it has are three of the new corvettes and frigates, three elderly British built frigates (1,540 tons each), and two U.S. built corvettes (1,100 tons each). There are about fifty smaller patrol craft, ten of them armed with Iranian versions of Chinese anti-ship missiles. Chief among these is the Nasr 1. There are another few dozen mine warfare, amphibious, and support ships. The three most powerful ships in the fleet are three Russian Kilo class subs. Most of the foreign built ships are serving way past their retirement date. There are about fifty mini-subs, most of them built in Iran. There are several thousand marines and twenty or so aircraft and helicopters.
The Iranian Navy is led by officers who think along more conventional lines. Western ship commanders generally have good professional relationships with their Iranian counterparts, even when the Iranian Navy is under orders to give Western ships a hard time. If an Iranian captain radios that “he has his orders” it means he will follow through with whatever bizarre actions he has been ordered to carry out but will be apologetic about it to his foreign peers.
The Iranian Navy has fewer options than the Revolutionary Guard, simply because the navy has fewer and larger (easier to spot and hit) ships. Since 2005 the navy has generally been stationed on the Indian Ocean and the Caspian Sea, while the Revolutionary Guard has been given responsibility for the Persian Gulf and protecting all those Iranian oil facilities along the coast. Actually, the Revolutionary Guard is there more as a threat to Arab oil fields and tankers because the Arabs and their Western allies have control of the air and can destroy Iranian oil fields and tankers that way.
What the Iranians hope to do at sea is create as formidable a threat as possible, even if this threat, in the form of suicidal speedboats and missile boats backed up by shore-based anti-ship missiles, is short-term. In the long run, any Iranian naval power is toast.