Iran’s “mosquito fleet” still controls the Strait of Hormuz. The waterway narrows to 21 nautical miles. In that corridor, small IRGC attack boats keep commercial shipping at risk despite losing roughly half their numbers, US commanders say.
What the fleet looks like
The IRGC navy operates more than 1,500 small vessels, according to the New York Times. The boats carry anti-ship missiles including the Nasr, Kousar, Ghader, Zafar and the long-range Abu Mahdi. Some exceed 100 knots, about 185 kilometers per hour.
This force sits outside Iran’s conventional navy. Tehran created it in 1986, after regular naval officers hesitated to attack oil tankers carrying Iraqi-allied cargo during the Iran-Iraq war. The doctrine that followed was blunt: big ships lose to the US Navy, small hidden boats do not.
Hidden in caves
Most of the boats are too small for satellite imagery to track. They dock inside deep caves carved into the coastline and launch within minutes, analysts say. The IRGC has built at least 10 fortified bases for these craft along the Gulf coast.
Said Golkar, a Guard expert and political science professor at the University of Tennessee at Chattanooga, called the fleet “a guerrilla formation at sea.” The tactic is simple. Strike fast. Retreat fast.
How much has been destroyed
In early April, US General Dan Caine said more than 90 percent of Iran’s conventional navy had been sunk, including major warships. He estimated that roughly half the fast attack boats were also destroyed.
The rest still operate. Inside the strait, even a handful of fast boats armed with missiles can threaten commercial shipping.
At least 20 vessels have been attacked during the war, according to the International Maritime Agency. The IRGC has claimed responsibility in only a handful of cases.
Why US warships stay outside
American warships avoid lingering inside the strait. Maneuvering room is limited. Reaction time against a drone or missile from a hidden coastal position is nearly zero, experts warn.
US vessels enforcing the blockade work from the Gulf of Oman or the Arabian Sea. There they can monitor traffic while staying harder to reach. Iran has threatened to push operations into the Red Sea through its allies in Yemen.
The asymmetric problem
A small missile boat costs a fraction of a destroyer. Losing one costs less still. The US can sink dozens. If a single boat breaks through and hits a tanker, global oil markets feel it within hours.
That is the calculation Tehran has made. The regular navy is gone. The conventional military is heavily degraded. The mosquito fleet, scattered across hidden bases along 1,500 kilometers of coastline, keeps Hormuz dangerous at low cost.
What this means
The ceasefire expires April 22. A deal would not remove the fleet. Dismantling it means locating and destroying dozens of hidden bases along Iran’s coast, a far harder job than sinking warships in open water.
For now, the strait stays closed to any vessel that refuses Iran’s transit fees or protocols. The mosquito fleet is the enforcement mechanism.
