Skirting around the vast oil tankers anchored patiently in the Strait of Hormuz, Iran’s so-called ‘mosquito fleet’ is locking down the critical waterway stuck under a double-blockade.
Last Wednesday, small boats belonging to the navy of Iran’s powerful Revolutionary Guard attacked three large container ships, two of which were forced to head to Iranian ports for allegedly trying to pass through the Strait without Tehran’s permission.
Donald Trump said Iran’s navy is “laying at the bottom of the sea, completely obliterated”, but that “what we have not hit are their small number of, what they call, ‘fast attack ships,’ because we did not consider them much of a threat”.
Seen as Tehran’s second navy, a swarm of speedboats crosses across the narrowest part of the Strait, difficult to track and often carrying weapons onboard. It is now a serious concern for vessels seeking transit through the waterway.
The Epaminondas ship is seen during seizure by the Islamic Revolutionary Guard Corps (IRGC) in the Strait of Hormuz, Iran, in this image obtained by Reuters on April 24, 2026. (via REUTERS)
Speaking to the New York Post, former Pentagon official and Atlantic Council fellow Alex Plitsas said: “They call them ‘mosquito fleets’ because they’re small and annoying – and they hit. But they’re enough to bite and be obnoxious.”
The boats allow Tehran to shutdown the Strait in a cheaper, more flexible and less costly way than using its larger vessels including frigates and submarines, many of which were damaged in US-Israeli bombardment.
“The Islamic Revolutionary Guard Corps (IRGC) uses a ‘mosquito fleet’ instead of large warships,” Saeid Golkar, a professor of political science at the University of Tennessee in Chattanooga, told Spanish outlet El Pais.
A screen capture from a video said to show the seizure of the container ships MSC Francesca and Epaminondas in the Strait of Hormuz, broadcasted on Iranian State TV, showing Iranian troops departing one of their ‘mosquito’ boats (IRIB)
The vessels operate “in swarms, approaching at high speed from different directions. In a narrow area like the Strait of Hormuz, this puts significant pressure on US naval forces”.
The boards are operating a “form of maritime guerilla warfare focussed on harassment, disruption and increasing the cost of US operations, rather than trying to win a traditional battle”, Mr Golkar added.
It only takes several small boats to seize an oil tanker, therefore driving up the fears of other tankers which choose instead to remain anchored, and as a result pushing up oil prices.
“They’ve realised they don’t have to actually mine the straits. A couple of drones and a couple of small boats… have been able to choke the world’s largest strategic waterway at risk without actually permanently closing it — and wreaking havoc on the markets,” Mr Plitsas added.
The Strait of Hormuz has not been freely open for traffic for two months (Getty)
Iranian political scientist Vali Nasr, a former advisor to the Barack Obama administration, told El Pais that “cheap weaponry” is sufficient to deter vessels venturing into the Strait of Hormuz.
Control over the waterway has been a crucial element of Iran’s war with the US, which began with US-Israeli attacks on 28 February.
Without the means to match the sheer output of drones and missiles by the US and Israeli militaries, Tehran has been waging war on different fronts in order to level the playing fields.
In normal times, 20 per cent of the world’s oil flows through the Strait of Hormuz. Iran’s blockade of the waterway, and a subsequent blockade of Iranian ports in the Gulf of Oman by the US military, has seen energy prices skyrocket as commercial vessels including fuel tankers are blocked from passage.
Oil prices skyrocketed to more than $125 a barrel on Thursday amid ongoing fears that the prolonged crisis in the Strait of Hormuz could damage the global economy.