Iran’s Midget Subs and Drone Boats Challenge Hormuz Security

Iran’s Asymmetric Naval Tactics

Iran has intensified its efforts to challenge the security of the Strait of Hormuz, a critical maritime passage for global energy trade. The strait, spanning 104 miles between the Persian Gulf and the Gulf of Oman, facilitates approximately 20% of the world’s liquefied natural gas (LNG) and 25% of seaborne oil shipments annually. Its strategic significance has prompted Iran to deploy asymmetric tactics, including the Ghadir-class midget submarines, manned speedboat swarms, and electronic warfare measures such as GPS jamming. While kamikaze drone boats are not confirmed as a deployed tactic, their potential role in future operations is under analysis.

Ghadir-Class Midget Submarines

The Ghadir-class midget submarines, developed using North Korean designs, are central to Iran’s naval strategy in the Persian Gulf. These vessels, typically under 30 meters in length and displacing around 120 tons, are tailored for the shallow, sonar-challenged waters of the strait. Their small size enables operation in thermocline layers, evading detection by acoustic and magnetic sensors. With a submerged speed of 7 knots, they can approach targets undetected, launching torpedoes or mines at surface vessels.

IRGC Ambush Operations

Iran’s Islamic Revolutionary Guard Corps (IRGC) has reportedly used these submarines for ambush operations against oil tankers and naval escorts. Simulations suggest they could target U.S. assets such as Arleigh Burke-class destroyers and MH-60 helicopters. Additionally, midget submarines are believed to play a key role in covert mine-laying. While Iranian mines may lack the sophistication of advanced Western systems, their deployment could disrupt maritime traffic by creating hazardous zones in the strait.

Mine Deployment and Threats

Iran has deployed a combination of contact mines and sensor-activated mines to key areas of the strait. Contact mines detonate upon physical contact with a vessel, while sensor-activated mines use acoustic or magnetic detection to identify targets before triggering. Sources indicate dozens of mines—estimated at 12–20—have been placed at chokepoints, though most locations are known to U.S. and coalition forces. These mines pose a significant threat to commercial and military vessels navigating the strait.

Conflict and Military Escalation

During the 2023–2025 conflict, Iran’s tactics contributed to a de facto closure of the strait. At least 16 vessels, including oil tankers and commercial ships, were attacked, with casualties reported among both Iranian and U.S. forces. The U.S. sank an Iranian warship off the coast of Sri Lanka in late 2025, resulting in 87 Iranian casualties. These incidents highlighted the strait’s vulnerability and led to increased U.S. military presence to protect commercial traffic.

Manned Speedboat Swarms

Manned IRGC speedboats have also been extensively used for swarming attacks. These fast, small vessels operate in coordinated groups to overwhelm enemy defenses, targeting commercial ships and naval patrols. The 2023–2025 conflict saw at least 16 vessels attacked, with casualties reported among both Iranian and U.S. forces. The effectiveness of these swarms underscores Iran’s reliance on asymmetric warfare to counter superior naval power.

GPS Jamming and Electronic Warfare

GPS jamming has been a recurring tactic in the Strait of Hormuz, disrupting drone and ship navigation. Iran’s interference, combined with actions by neighboring states like the UAE and Oman, has created widespread electronic chaos. This has led to distorted ship tracking data on platforms like VesselFinder, where vessels appear in geometric clusters due to signal interference. While GPS jamming poses a lower direct threat to ships, it significantly impacts maritime safety and commercial operations.

Strategic Implications of Hormuz Disruption

Iran’s strategies have had profound economic and geopolitical consequences. The threat of minefields and ambushes has reduced shipping through the strait, affecting 3,000 vessels and 20,000 crew members. The U.S. has since agreed to provide military escorts for commercial traffic, reflecting the strait’s critical role in global energy markets. However, Iran’s continued use of asymmetric tactics highlights the region’s vulnerability to destabilization, with potential ripple effects on global oil prices and international trade.