Assessing the State of Iran’s Naval Infrastructure and Tactics

Assessing the State of Iran’s Naval Infrastructure and Tactics

Executive Summary:

• The launch of the U.S.–Israeli strikes on February 28 devastated Iran’s conventional navy—the Islamic Republic of Iran Navy (IRIN)—sinking numerous frigates, corvettes, and submarines while docked or at sea.
• The Iranian Revolutionary Guard Corps Navy (IRGCN) remains dangerous, despite heavy losses, due to its decentralized structure and asymmetric warfare tactics. 
• The destruction proved that expensive, conventional fleets are still vulnerable to superior forces, and will likely solidify Iran’s reliance on asymmetric tactics, including land-based missiles, drones, and speedboats.

The launch of Operation Epic Fury on February 28 aimed to destroy much of Iran’s military capabilities. One day into the joint U.S.–Israeli attacks, U.S. President Donald Trump declared that Iran’s navy “will soon be floating at the bottom of the sea” (X/@WhiteHouse, March 1).  Iranian naval infrastructure has indeed suffered crippling losses. The country appears, however, to maintain an active presence in the most sensitive parts of the Persian Gulf. It is therefore important to assess these navies’ levels of destruction and their current operational state. This major engagement, furthermore, likely portends changes for the future of both Iranian and international naval strategy. 

Two Navies, One Fate 

Iran maintains two separate naval institutions, the Islamic Republic of Iran Navy (IRIN) and the Iranian Revolutionary Guard Corps Navy (IRGCN). The IRIN  is Iran’s conventional navy and consists of large surface ships, frigates, corvettes, and submarines, used mainly for diplomacy, long-range patrols, and counter-piracy operations. The IRGCN evolved in the midst of the Iran–Iraq war (1980-88). Intended mainly for littoral operations—particularly in the Persian Gulf—the IRGCN specializes in guerrilla-style naval warfare and tactics, using fast-attack craft, short-range cruise missiles, drones, torpedoes, and mines (Gulf International Forum, March 2026). In terms of personnel, the IRGCN is slightly larger, with 20,000 pre-war members opposed to 18,000 for the IRIN.

The IRIN has a formal command structure similar to that of other national navies and is led by Rear Admiral Shahram Irani, a Sunni Kurd. The IRGCN, on the other hand, has a decentralized command structure that seeks to foster resilience and initiative under pressure. Small IRGCN units are spread widely in concealed, hardened positions throughout the islands and inlets of the Persian Gulf, making them difficult to locate and eliminate. The entire region adjacent to the Strait of Hormuz is honeycombed with caves and hidden valleys, well-suited for concealing mobile missile systems.

Iran’s naval losses to U.S. forces during Operation Praying Mantis in April 1988 persuaded Tehran to shift to an asymmetric war model, while retaining a conventional force. After international patrols in the Gulf of Aden in 2008, Iran also began to focus on the development of a blue-water navy that would, in the words of Rear Admiral Habibollah Sayyari, deploy “from the North Pole to the South Pole,” including “warships in international waters off the [U.S.] coast … However, we will never enter the maritime borders of others, and we will not allow anybody to enter even a centimeter into our territorial waters” (Times of Israel, September 22, 2012). In practice, IRIN ships are responsible for defensive operations in the Gulf of Oman, the Caspian Sea, and the Arabian Sea, while the IRGCN secures the Persian Gulf. 

Opening Phase Attacks 

The Israeli–American opening strikes targeted Iranian radar, communications, and naval assets at its chief port of Bandar Abbas. These were followed by strikes on the ports of Chah Bahar and Bushehr, the coastal batteries at Jask, the year-old naval base at Bandar Sirik, and the fast-attack craft base at Qeshm (Marine Forum, March 5; Q News, March 31). Bandar Abbas is home to the headquarters of both the IRIN and IRGCN. The attacks diminished Iran’s integrated surveillance and maritime and air defense systems (Gulf International Forum, March 2026). IRGC speedboat bases were also struck, destroying as much as 70 percent of their inventory (Marine Forum, March 5). 

On March 18, the Israeli Air Force attacked the Caspian Sea port of Bandar Anzali—headquarters of the IRIN’s northern operational zone—to disrupt the shipping of Russian military supplies to Iran ( Ynet News, March 18; Militarnyi, March 19). Most of Iran’s Caspian fleet was destroyed, including a minesweeper, missile boats, the corvette Hamzeh (former personal yacht of Reza Shah, launched in 1936), and the Moudge-class frigate Deylaman, which sank on March 18.

Targeting Naval Leaders 

The Israeli–American campaign sought to “decapitate” Iran’s naval leadership in addition to its political leaders. On March 26, Israel claimed it had killed the head of the IRGCN, Commodore Alireza Tangsiri. He is a U.S. Specially Designated Global Terrorist (SDGT) and is believed to be responsible for leading the Iranian operations that closed the Strait of Hormuz (Times of Israel; U.S. Department of Defense; Al-Jazeera,  March 26). The deputy chief of IRGC naval intelligence, Behnam Rezaei, was also killed in the Israeli attack (Iran International, March 26)

Sinking of the Moudge-Class Light Frigates 

Iranian-built ships of the Moudge-class made up the core of the regular navy’s fleet, combining air-defense systems, anti-ship cruise missiles, and anti-submarine capabilities (Gulf International Forum, March 2026; Naval News, March 2). Iran identifies these ships as destroyers, but they are closer in size to light frigates or even corvettes. These ships, however,  were unable to mount a defense when attacked by U.S. warplanes.

The IRIS Jamaran was sunk at its mooring by an airstrike at Chah Bahar on March 1, while the Sahand sank after an airstrike on Bandar Abbas. The Sahand had already sunk once in an accident likely caused by a design flaw while in harbor in July 2024 before being repaired and recommissioned in November 2025 (Business Insider, July 12, 2024). The IRIS Zagros, intended to be a Moudge-class frigate, was converted to a signals intelligence (SIGINT) ship after a construction accident, and was sunk by U.S. airstrikes in early March. 

The Moudge-class 1500-ton frigate Dena was sunk south of Sri Lanka, 2,000 miles from Iran, on March 4. It lost up to 80 of its 180-man crew. It was struck by a torpedo from USS Charlotte, a Virginia-class submarine, making it only the third ship to be sunk by a torpedo since 1945. The Dena was returning to Iran from the Indian-hosted Exercise MILAN 2026 in the Bay of Bengal. The exercise included ships from 18 navies and aircraft from three others, including a U.S. P-8A Poseidon maritime patrol and reconnaissance aircraft, which may have tracked the Dena (U.S. Navy, February 25; Military.com, March 11). 

Other Iranian ships took part in the MILAN 2026 exercise. These included the replenishment ship IRIS Bushehr and the auxiliary ship IRIS Lavan, a Hengam-class landing ship commissioned in the 1980s. Fearing further submarine attacks, the Bushehr sought refuge in Sri Lanka following the sinking of the Dena. After its crew of 208 was taken off in Colombo, the Bushehr was interned at Trincomalee (Naval News, March 5). Citing technical issues, the Lavan and its 183-man crew found refuge in the Indian port of Kochi (Deccan Herald, March 14). 

Sinking of Alvand-class Frigates and Bayandor-class Corvettes

Iran’s aging navy included four British-built frigates commissioned in the 1960s by the Imperial Iranian Navy and refitted several times since. Known as the Alvand-class, these ships were closer in size to corvettes than frigates. One of the ships from this class, the IRIS Sahand, was sunk by U.S. forces during the so-called Tanker War (1981–1988) when Iraq and Iran both targeted oil tankers and other merchant shipping in the Persian Gulf. 

The IRIS Alvand and the IRIS Sabalan were sunk during the February 28 attack on Bandar Abbas. The last remaining ship of the class, the Alborz, was in dry-dock during the attack (Gulf International Forum, March 2026). The Sabalan had already been badly damaged in Operation Praying Mantis in 1988.

In the 1960s, the United States supplied Iran with four Texas-built corvettes, which came to be known in Iran as the Bayandor class. Two were sunk during the Iran–Iraq War of the 1980s, while the remaining two, the IRIS Bayandor and IRIS Naghdi, were destroyed in a U.S. strike on Iran’s Konarak naval base, an important outlet on the Gulf of Oman (Naval News, March 4).

The Fate of Iran’s Submarine Fleet 

The IRIN maintains only a small number of diesel-electric attack submarines, which it struggles to keep in service. The shallow waters of the Persian Gulf present operational challenges for these larger subs. The IRIN therefore has a flotilla of 23 Ghadir-class diesel-electric mini-submarines for use in the Gulf. Patterned on a North Korean design, the mini-subs are capable of firing both torpedoes and missiles (Nuclear Threat Initiative, September 18, 2025). 

The IRIS Fateh, the first of four Fateh-class submarines, was reportedly destroyed by March 3 (Gulf News, March 4). Armed with torpedoes, mines, and cruise missiles, the Fateh was the most advanced of Iran’s underwater craft (Naval News, February 19, 2019). The IRIS Taregh, a 1990s-era Russian-built Kilo-class diesel-electric submarine—one of three renamed Taregh-class subs—was sunk alongside a pier at Bandar Abbas on February 28. The other former Taregh-class submarines, the Nooh and the Yunes, were trapped in the harbor by damage inflicted by airstrikes, though one report suggests the Yunes may have left the harbor before the strikes (Maritime Executive, March 1; Marine Forum, March 5).

Destroying the IRGC Navy 

The IRIS Shahid Bagheri, an innovative drone carrier, was one of the first U.S. targets. Operated by the IRGCN, the Shahid Bagheri was a converted South Korean container ship of 42,000 tons, refitted with a 180-meter ski-jump style flight deck and launched in November 2024. The ship carried a variety of aerial drones, helicopters, and cruise missiles and was capable of deploying guided sub-surface drones and up to 30 small high-speed patrol craft (Naval News, February 6, 2025; Tasnim News Agency, February 6). The valuable ship, which had only entered service in February 2025, was disabled by U.S. airstrikes on March 2 (Naval News, March 6; Gulf International Forum, March 2026).

The IRIS Shahid Mahdavi was a converted South Korean-built container ship. As a mobile base for drones, helicopters, and ballistic missiles, the ship was designed to contribute to an asymmetrical naval strategy through long-range operations. The Shahid Mahdavi sank in the Gulf of Oman after strikes by U.S. AGM-158C long-range anti-ship missiles (LRASM) (Marine Forum, March 5).

IRGCN Shahid Soleimani-class Corvettes 

The domestically-built Shahid Soleimani-class catamaran-style corvettes were constructed with radar-reducing aluminum hulls and could reach speeds of up to 45 knots. Vertical Launch Systems (VLS) allowed the deployment of Nawab short-range, infrared-homing air defense missiles, Sayyad-3G surface-to-air missiles, and Abu Mahdi anti-ship cruise missiles. Helipads accommodated reconnaissance or attack helicopters. 

The lead ship of the class, the IRIS Shahid Soleimani, was sunk at Bandar Abbas on March 3. The next day, the IRIS Shahid Sayyad Shirazi was struck by U.S. missiles and left burning at sea. The corvette was only operational for a few weeks before its destruction (Naval News, March 4). The IRIS Shahid Nazeri was moored at Bandar Abbas when U.S. attacks began and was likely disabled or destroyed at that time (Maritime Executive, March 1). The fate of the year-old IRIS Shahid Rais Ali Delvari was not immediately clear, but by March 11, U.S. CENTCOM claimed it had destroyed the last of the four Shahid Soleimani-class warships (X/@CENTCOM, March 11).  At half the size of the Shahid Soleimani-class, the catamaran missile corvette IRIS Abu Mahdi al-Muhandis did not yet have its anti-aircraft weapons installed when it was hit and sunk at Bandar Abbas on March 11 (Janes.com, March 11).

The Forward Base Ships 

Iran’s Forward Base Ships are comparable to the U.S. Navy’s Expeditionary Mobile Base ships and are designed to handle both sea and air operations. The largest of these, the 230-meter IRIS Makran, was converted from a Japanese oil tanker and operated by the IRIN. The Makran was capable of supporting helicopter operations and acting as a base for operations by Special Forces groups like Iran’s Special Boat Service (SBS) (Naval News, March 2; Naval News, March 11). It was last seen burning at Bandar Abbas after a March 1 U.S. airstrike (Naval News, March 4).  

IRGCN forward base ships include the IRIS Shahid Roudaki, a former Italian-built cargo ship redesigned to accommodate helicopters, drones, missiles, and electronic warfare systems. The Guards also operate the undeclared forward base ship MV Saviz. It is still officially listed as a civilian merchant ship, despite being attacked with limpet mines in the Red Sea in a 2021 Israeli Defense Forces (IDF) operation. The current status of both these ships is unclear.

Iran’s Patrol Boat Strategy 

Iran’s wartime maritime strategy calls for denying access to the Persian Gulf and leveraging the complex geography of the littoral region to implement in-depth defensive measures using modern technology. A tactic favored by the IRGCN, but not yet used in the current conflict, is the swarm attack by highly maneuverable armed speed-boats, manned or unmanned. Defense against such attacks calls for eliminating as many of the boats as possible at a distance; once in close range, the multiple targets created by the “swarm” can overwhelm even modern defensive systems. In the case of speedboats armed with torpedoes or small cruise missiles, this can present a serious threat  (Naval News, December 14, 2021).

Iran’s small boats have also taken a beating from airstrikes. Particularly, a flotilla of IRGCN Tondar-class patrol boats at Bushehr naval base and IRGCN Zolfaghar-class fast attack craft (patterned after a North Korean design). Some of these attacks took place at the island of Qeshm in the Strait of Hormuz, which hosts fast attack boats and missile batteries intended for use in closing the strait (Al-Jazeera, March 17). 

Controlling Hormuz 

Iran’s defense of the Strait of Hormuz is largely land-based. Iran mainly defends the strait by aerial drones and a variety of land-based missiles and sea drones launched from hardened positions rather than using conventional naval vessels. With the addition of mines dropped from small speedboats, passage through the strait becomes a precarious enterprise, even for powerful naval vessels. Where once carriers could work their way up the Persian Gulf, today they remain distant in the safety of the Arabian Sea (Responsible Statecraft, March 31).

Mines can have a deterrent effect greater than their operational reality. Mine-laying craft have been targeted by U.S. strikes, though estimates suggest as much as 80 percent of Iran’s mine-laying capacity survived the first two weeks of intense airstrikes (Naval News, March 11). Any attempt to clear mines from the strait could encounter resistance from high-speed attack craft, drones, and shore-fired missiles. Intense aerial support would be necessary to find and counter such threats.

Conclusion

By April 1, U.S. authorities were claiming the destruction or disabling of over 155 Iranian warships (U.S. Department of Defense, April 1). The utter devastation of most of the Iranian Navy in a matter of days likely confirmed Iranian naval planners’ suspicions that the highly mobile and asymmetrical approach of the IRGCN was better suited to confrontations with superior forces (Middle East Institute, January 31, 2012). One result of the campaign has been to reduce the size and influence of the professional Iranian Navy and its leadership, with the IRGCN now ascendant.

Israel and the United States have succeeded in incapacitating Iran’s blue-water navy by aerial or submerged attacks. The IRGCN’s small craft, however, have proven more difficult to deal with. These small crafts are not so much a singular naval presence as part of an integrated defense scheme that exploits geographical advantages while deploying sensors, mobile missile systems, mines, and fast-attack craft responsive to a dispersed command-and-control structure—one capable of considerable resiliency under pressure.

The Israeli–U.S. surprise attack on February 28 allowed the partners to strike Iranian warships while still in port. The ships of the IRIN and the IRGCN were useful to the regime, if accident-prone, but it could not have escaped the attention of Iranian naval planners that the United States could sink their fleet at will. The destruction of most of Iran’s navy did not prevent Iran from closing the Strait of Hormuz; there was, in any case, no role for its conventional ships in the asymmetrical warfare being practiced successfully by the IRGC’s remaining fast-boats. One lesson that might be drawn from this conflict is the futility involved in trying to maintain an expensive naval arm that is ultimately incapable of engaging with superior forces.