Iran Deploys Small Vessels to Disrupt Shipping in Strait of Hormuz

Iran has developed a naval strategy centered on small, fast vessels to disrupt shipping through the Strait of Hormuz after U.S. and Israeli attacks destroyed much of its traditional fleet. The approach relies on dozens of small military boats armed with missiles, machine guns and drones.

These vessels operate in coordinated groups, enabling them to target large cargo ships carrying substantial loads. The tactic emerged after Iran's larger naval assets were largely eliminated. He added that small fast-attack boats were not viewed as a significant threat and therefore were not targeted.

Less than 10 days later, on April 22, Iranian forces using the small vessels seized two large container ships departing the Strait of Hormuz.

The small-boat fleet was first developed during the Iran-Iraq war to interfere with oil tankers supporting Iraq. Michael Eisenstadt, director of the Military and Security Studies Program at the Washington Institute for Near East Policy, said the boats function similarly to U.S. torpedo squadrons used in World War II.

Eisenstadt stated that Iran possesses more than 1,000 of these vessels. They are armed with rockets, machine guns, anti-ship missiles and mines. Their effectiveness stems from operating in large numbers, which complicates efforts to counter them. In March, Iran demonstrated the capability by launching a few dozen drones against oil tankers and cargo ships in the Persian Gulf, according to Eisenstadt.

Combined with thousands of support drones, the fleet exceeds what is required to restrict passage through the strait, he said. The vessels' proximity to the waterway further aids these operations.

Its conventional navy has suffered heavy losses, while the naval component of the Islamic Revolutionary Guard Corps, known as the Pasdaran, remains largely intact. A Hudson Institute report noted that most sunk platforms belonged to the regular armed forces, whereas the Revolutionary Guard's asymmetrical assets designed for the Strait of Hormuz were largely unaffected.

Eisenstadt said the Revolutionary Guard navy operates near the strait and has long been the primary force threatening maritime traffic there. The force is supported by coastal bases, radar, mines, drones and some civilian vessels. Some boats have been configured as explosive-laden suicide craft.

The overall system also incorporates cruise missiles, anti-ship ballistic missiles and Shahed drones. This creates multiple layers capable of striking targets across the Gulf.

Eisenstadt said these tunnels and the vessels inside would be difficult to destroy from the air. A sustained campaign would be required to eliminate the fleet. "So unless the US is willing to land ground forces to conduct raids inside this complex network of tunnels, I don't think they will be able to destroy these capabilities," Eisenstadt said.

The Hudson Institute report described the strategy as focused on denial rather than control. It raises the costs of using the waterway and maintains pressure without requiring full-scale naval battle. The assets can be contained but resist complete destruction.