Iran operates submarines in the Strait of Hormuz and the broader Gulf of Oman. The fleet is not large, and the vessels are not modern by the standards of major naval powers. What they represent is a persistent underwater presence in one of the world’s most difficult antisubmarine warfare environments — a shallow, thermally layered, acoustically cluttered body of water where detection is genuinely hard and where even a small submarine with limited capability poses a disproportionate threat to shipping and to surface naval forces.

Iran has invested more systematically in anti-ship missile capability than any other aspect of its naval force development over the past three decades. The investment reflects the operational logic of the IRGCN’s Hormuz doctrine: surface ships and tankers transiting the strait in a contested environment must be threatenable from multiple vectors simultaneously, and missiles — launched from shore, from surface vessels, from aircraft, and eventually from submarines — provide the most cost-effective way to achieve that coverage. The resulting arsenal is among the largest and most diverse anti-ship missile inventories of any regional power.