The shallow, sun-warmed waters of the Strait of Hormuz barely reach 60 meters at their deepest point along the main shipping lanes. That is far too shallow for most military submarines. It is exactly the environment Iran’s Ghadir-class mini-submarines were built to exploit.
Displacing roughly 120 tons and stretching less than 30 meters long, these boats can settle onto the seabed in depths where a U.S. Navy Virginia-class attack submarine could never operate. They carry torpedoes designed to be launched without the vessel ever breaking the surface. And according to the U.S. Defense Intelligence Agency, Iran has made them a cornerstone of its strategy to control the narrow waterway through which roughly a fifth of the world’s petroleum supply passes every day.
A submarine designed for a specific battlefield
The DIA’s Iran Military Power report, first published in November 2019 and introduced by DIA official Christian Saunders, remains the most detailed unclassified U.S. government assessment of Iran’s naval posture. It describes a deliberate Iranian investment in small submarines suited for the Persian Gulf’s confined, acoustically cluttered waters. The report treats the Ghadir fleet as a key element of what analysts call asymmetric naval warfare: rather than matching a superior navy ship for ship, Iran aims to threaten, delay, and complicate any adversary’s operations in the strait.
The Ghadir’s small size is both its limitation and its advantage. In the Persian Gulf, constant noise from commercial tankers, oil platforms, and shallow-water reverberation makes sonar detection unreliable. A 120-ton submarine sitting quietly on a sandy bottom can blend into that background in ways a 7,000-ton attack submarine never could. Western anti-submarine warfare crews have trained extensively against this kind of threat, but even experienced operators acknowledge that finding a quiet diesel boat in littoral waters remains one of the hardest problems in naval warfare.
Iran has also fielded the larger Fateh-class submarine, a semi-heavy boat displacing around 527 tons that can operate in slightly deeper waters and carry a heavier weapons load. Together, the Ghadir and Fateh classes give Iran a layered undersea capability: one optimized for the shallowest coastal zones, the other able to push farther into the Gulf of Oman and beyond.
Missiles that extend the threat far beyond the strait
Iran’s submarine fleet does not operate in isolation. In a 2024 weapons test reported by the Associated Press, Iran fired an anti-ship cruise missile with a range exceeding 600 miles. That distance covers most of the Arabian Sea and reaches well into the Gulf of Oman, meaning Iranian shore-based launchers could target warships long before they approach the strait itself.
The combination creates a problem military planners describe as a layered threat. A carrier strike group approaching the Gulf would face long-range cruise missiles at several hundred miles out, then medium-range anti-ship missiles closer in, and finally torpedo-armed submarines lurking in the shallow water of the strait itself. Defending against all three simultaneously forces a navy to spread its sensors and weapons across a vast area, and any gap in that defense becomes an opportunity for Iran.
This is not a theoretical concern. The Houthi maritime campaign in the Red Sea throughout 2024 and into 2025, which relied on Iranian-supplied missiles and drone boats, demonstrated that asymmetric naval threats can disrupt global shipping routes for months. Iran watched that campaign closely, and Western defense officials have noted that lessons from the Red Sea are almost certainly being incorporated into Iranian naval planning for the Persian Gulf.
What analysts still cannot confirm
No publicly released satellite imagery or declassified intelligence has pinpointed Iranian mini-submarines at specific locations within the Strait of Hormuz on any given date. The DIA report describes capabilities and strategic intent, but the gap between what Iran can do and what it has actively deployed at a particular moment is significant. Confirming that specific Ghadir boats are stationed at specific coordinates requires classified surveillance data that remains unavailable to the public.
The exact number of operational Ghadir-class hulls is similarly uncertain. Iran has announced production of multiple boats over the past decade, but maintenance cycles, mechanical reliability, and crew readiness all determine how many could actually sortie on short notice. Western intelligence agencies track these figures, yet the numbers that surface in public reporting tend to reflect total production rather than operational availability. A fleet of 20 hulls on paper might translate into six or eight boats ready to deploy in a crisis.
There is also no combat record to evaluate. No engagement involving an Iranian mini-submarine has been publicly documented, so assessments of their real-world lethality rest on exercises, technical specifications, and modeling. The Persian Gulf’s shallow depths limit a submarine’s evasion options once it is detected, and U.S. Fifth Fleet assets, including helicopters, patrol aircraft, and surface ships assigned to Task Force 52, train specifically for this scenario. Whether a Ghadir crew could successfully attack a warship and survive long enough to reload or withdraw is a question that remains genuinely open.
Perhaps the most consequential unknown is intent. A torpedo attack from a mini-submarine requires the crew to position itself within a few miles of its target, accepting enormous personal risk and near-certain retaliation. Whether Iran would actually order such an attack against a major naval power, or whether the submarines serve primarily as a deterrent and intelligence-gathering tool, is a question that divides analysts. The boats are most valuable as a threat that forces adversaries to spend time, money, and attention on anti-submarine warfare. Actually using them could trigger a response Iran’s broader military could not absorb.
Why the strait still dominates the calculus
Roughly 21 percent of global petroleum liquids consumption transits the Strait of Hormuz daily, according to the U.S. Energy Information Administration. No pipeline network or alternative route can replace that volume quickly. A credible threat to close or disrupt the strait, even temporarily, gives Iran leverage that extends far beyond its conventional military strength.
That leverage shapes every negotiation Iran enters, from nuclear talks to sanctions discussions. As long as Tehran can credibly threaten to choke the world’s most important energy corridor with mines, missiles, and submarines, it holds a card that no adversary can entirely neutralize without accepting costs measured in oil-price spikes and global economic disruption.
Iran’s mini-submarine program is best understood in that context. The Ghadir and Fateh boats are not designed to win a prolonged naval war. They are designed to make the opening hours of any conflict in the Gulf as costly and chaotic as possible, buying Iran time and raising the threshold for military action against it. As of mid-2026, with tensions over Iran’s nuclear program unresolved and the memory of Red Sea shipping disruptions still fresh, that calculus shows no sign of changing.
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*This article was researched with the help of AI, with human editors creating the final content.
