Strait of Hormuz: Iran's no-go zone and the danger of mines

As we learnt at the weekend, Iran is said to have laid mines in the Strait of Hormuz. Presumably. There is no evidence of this and the probability is low. But this allegation can cause a great deal of uncertainty and unrest. That is the purpose. Does Iran have anything to gain from mining its own waters? No.

On the morning of 9 April 2026, the Revolutionary Guards published a navigation map that officially declares the internationally established shipping routes of the Traffic Separation Scheme (TSS) to be a „Danger Zone“. This has led to a situation in which transit is increasingly dependent on Iranian authorisation, prior inspection and fee demands. Instead of free passage under international maritime law, the threat of military force against unauthorised ships applies. The Tehran regime only needs to selectively control traffic, create uncertainty and increase the risk for shipowners, charterers and insurers to such an extent that economic coercion has the same effect as a physical blockade.

Asymmetric warfare and traffic control

One means of creating uncertainty is the threat of a mine hazard. According to specialist sources and risk analyses, Iran has had around 5,000 to 6,000 sea mines of various types for years. However, it is not the total number in the stockpile that is decisive, but the quantity that has been and/or can be deployed in the designated sea area.

The public picture of the situation remains blurred: in March 2026, reports ranged from fewer than ten to around a dozen to several dozen mines that had already been laid or prepared. An openly confirmed, reliable total figure is not yet available. In military terms, this lack of clarity is not a shortcoming, but part of the effect. In a bottleneck like Hormuz, a few credibly placed mines are enough to slow down traffic, force diversions, increase war risk premiums and tie up mine defence forces.

Iranian mines

A mixed arsenal of simple and more complex systems can be assumed for the range of types. These include classic anchor and contact mines. In addition, there are base mines with magnetic and acoustic sensors. These mines have a so-called "shipcount", which only detonates the mine after a certain number of passages. He also lists EM-52 and EM-56, bottom mines that have a drive. The military value of this arsenal lies not in its technical diversity, but in the combination of its operating principles: simple mines quickly create a risk on the ground. More complex systems prolong clearance times and increase insecurity.

In addition to the available arsenal, transport capability is an important criterion. Sutton and Arab News point out that small IRGC boats can transport two to three mines per trip. Due to its proximity to its own coast and a large number of small platforms, Iran can create a credible mine risk. Iranian propaganda videos demonstrate the transport of mines from helicopters. The small Ghadir submarines are said to have a mine-launching capability. Ultimately, the transfer of mines is also possible from civilian vehicles - dhows or fishing boats.

The threat

The real threat therefore arises from two factors: existing possibilities and the political will to deploy them.

The political will can be seen in the current transit controls, in the demand for fees and clearances and in the willingness to openly instrumentalise merchant shipping as a means of exerting pressure.

For the maritime situation assessment, it is not only decisive whether a large minefield has already been detected. The Tehran announcement alone is enough to increase the risk. In the context of the control regime, sea mines become the central instrument of „maritime coercion“.

The Marineschifffahrtleitung, an agency of the German Navy, states in its situation report of 9 April, not only because of the mine danger: „The attempt to pass the SoH at the present time is to be regarded as highly dangerous. A recommendation not to attempt this will continue to be issued by the MSchLtg to DEU shipowners.“

Text: hum / hsc