Islamic Republic of Iran Navy (Niru-ye Darya'i / IRIN)

The Islamic Republic of Iran Navy (IRIN; Niru-ye Darya’i-ye Jomhuri-ye Eslami-ye Iran) is Iran’s conventional regular navy, operating under the Artesh chain of command. It is distinct from the IRGC Navy (IRGCN), which controls asymmetric warfare in the Persian Gulf littoral. Where the IRGCN operates swarms of fast attack craft in confined waters, IRIN aspires to a blue-water capability — operating frigates, submarines, and support vessels in the Gulf of Oman, Indian Ocean, and beyond.

Fleet Composition

IRIN’s surface fleet is modest by regional standards. The Moudge-class frigates (Jamaran, Damavand, Sahand) are the most modern surface combatants, domestically built with a design lineage tracing to the British Vosper Mk 5. They carry anti-ship cruise missiles, a 76mm gun, and limited air defense systems. The older Alvand-class frigates (also Vosper-derived, delivered pre-revolution) remain in service despite their age. The fleet’s most notable addition is the Makran — a converted commercial tanker serving as a forward staging base, capable of carrying helicopters, fast boats, and supplies for extended deployments far from Iranian waters.

Submarine Force

IRIN’s submarine arm represents its most strategically significant conventional naval capability. Three Russian-built Kilo-class diesel-electric submarines (Type 877EKM), delivered in the 1990s, provide a credible torpedo and mine-laying capability. The Kilo-class is quiet when operating on battery power, and Western naval analysts assess that detecting these boats in the acoustically challenging waters around the Strait of Hormuz poses a genuine challenge. The domestically built Fateh-class semi-heavy submarine, commissioned in 2019, represents Iran’s most ambitious indigenous submarine program, assessed as capable of anti-shipping torpedo attacks and potentially submarine-launched cruise missiles. Additionally, the Ghadir-class midget submarines — assessed at 10 or more in service — are designed for special operations and shallow-water mine-laying in the Persian Gulf.

Blue-Water Ambitions

IRIN has conducted increasingly assertive deployments beyond the Persian Gulf. Task groups built around Moudge-class frigates and the Makran staging base have deployed to the Indian Ocean, Gulf of Aden (ostensibly for counter-piracy), and as far as the Atlantic and Baltic Sea. These deployments serve political signaling as much as operational purposes — demonstrating that Iran can operate naval forces at distance, even if the capability remains limited compared to regional competitors.

IRIN-IRGCN Division of Labor

The two Iranian navies maintain a geographic and doctrinal division of labor. IRGCN controls operations within the Persian Gulf and the Strait of Hormuz — the confined littoral environment suited to asymmetric swarming tactics. IRIN is responsible for the Gulf of Oman and blue-water operations beyond. In practice, the boundary is not always clean, and coordination between the two services has been a recurring challenge in Iranian defense planning. Sourced to ONI analysis, wartime operations would likely require IRIN submarines to operate in the strait approaches while IRGCN fast attack craft and coastal missiles dominate the confined waters inside — a combined effect that multiplies the anti-access threat.