TEHRAN – The Islamic Revolution Guards Corps (IRGC) Navy on Sunday seized another U.S. unmanned underwater vehicle in the Strait of Hormuz, the second such capture in less than three weeks.
A REMUS 600 autonomous underwater vehicle was trapped by IRGC naval forces, following the capture of a Dive LD unmanned sub-surface vessel on September 8, marking another American catch in the IRGC’s net.
The IRGC Navy said in a statement that its forces captured the advanced unmanned underwater vehicle in a “coordinated and complex operation” involving intelligence surveillance and electronic warfare. 
The statement said that the vehicle had been operating in the Strait of Hormuz for espionage purposes and identified it as a REMUS 600, saying the vessel has been placed in the hands of Iranian specialists to recover its data.
The REMUS 600, manufactured by Hydroid, is in service with the U.S. Navy under the designation Mk 18 Mod 2 and is nicknamed “Kingfish.”
The vehicle has a length of 4.3 meters, a diameter of 32.4 centimeters, and an endurance of 70 hours underwater at a standard speed of 3 knots, equivalent to 5.6 kilometers per hour.
The vessel is capable of reaching a maximum speed of 9.3 kilometers per hour and uses lithium batteries for propulsion.
The system is designed with a modular configuration allowing the installation of various payloads for military and non-military missions, including seabed mapping, downward-facing cameras for depth imaging, and side-scan sonar systems. Side-scan sonar means the sonar arrays are installed on the sides of the vehicle’s body.
The vessel was most likely deployed to the Persian Gulf for mine detection and countermeasures, using its sonar arrays to locate mines and prepare the area for neutralizing units, whether through explosives or anti-mine explosive projectiles.
The REMUS 600 has been exported to the militaries of Ukraine, Algeria, Canada, Japan, Ireland, Croatia, the United Kingdom, and New Zealand, in addition to the U.S. Navy.
The REMUS series also includes the REMUS 300, REMUS 6000, and REMUS 100, with the numbers indicating the depth each vehicle is capable of reaching.
Both the Dive LD and REMUS 600 are among the newest unmanned underwater vehicles in the U.S. Navy and feature autonomous technology, capable of carrying out missions without human intervention.
The issue of control underwater has many challenges, and for this reason, autonomous guidance is one of the preferred methods in this field, as it solves the important part of the challenge — control.
Iranian reports drew a parallel to Iran’s earlier experience with capturing enemy drones, stating that similar to what happened in Iran more than a decade ago, when, alongside domestic industries, obtaining various types of enemy drones helped improve understanding and accelerate development in that sector, obtaining these vessels in the field of unmanned underwater vehicles will now provide significant assistance to the development of knowledge and design and manufacturing capability in the country.
The IRGC Navy’s seizure of advanced U.S. underwater technology marks a significant development in the broader standoff, potentially providing Iran with valuable insights into American autonomous underwater systems at a time when Tehran is actively developing its own domestic capabilities in the field.
After the first seizure, American officials moved swiftly to downplay its significance. U.S. Central Command spokesman Captain Tim Hawkins acknowledged that an American unmanned underwater vehicle had malfunctioned “more than a day ago” while surveying regional waters, but insisted it was “an older model that neither collected sensitive data nor carried any classified sonar or radar equipment”.
Military experts and analysts paint a dramatically different picture. The capture of the REMUS 600 represents far more than the loss of a single vehicle — it hands Iran the Pentagon’s operational playbook for the Strait of Hormuz.
According to Iranian defense analysis, the vehicle’s mission memory, recorded routes, sonar data, search algorithms, navigation settings, and software configuration can provide a precise picture of how U.S. unmanned underwater vehicles operate in the Strait of Hormuz.
This intelligence windfall extends to understanding American tactics, data collection methods, and operational patterns.
The REMUS 600’s technical specifications underscore why its loss is significant. The vehicle can operate at depths of up to 600 meters, and some configurations can reach 1,500 meters.
It relies on an integrated suite of inertial navigation systems, Doppler Velocity Logs, acoustic navigation, and GPS for surface positioning — allowing it to execute missions autonomously without constant operator communication.
Its Synthetic Aperture Sonar (SAS) payload is particularly sensitive. High-frequency SAS systems process acoustic returns to generate photographic-quality seabed imagery with resolutions as fine as a few centimeters at ranges exceeding several hundred meters.
Replicating these transducer arrays and digital beamforming algorithms would equip Iran with foundational technology for detecting buried or tethered objects in turbid coastal waters.
The vehicle’s navigation architecture — pairing inertial navigation with Doppler Velocity Logs and acoustic transponders to maintain centimeter-level accuracy without surfacing — resolves critical dead-reckoning limitations that have long constrained Iran’s indigenous underwater programs.
Its high-density lithium-ion battery packs and specialized battery management systems provide direct templates for extending the operating radius of Iranian underwater weapons.
The comparison to Iran’s earlier capture of the RQ-170 Sentinel drone is unavoidable. More than a decade ago, obtaining that American aerial platform helped accelerate Iran’s development as an unmanned aerial power.
Now, with two complementary classes of American autonomous submersibles — the heavy Dive-LD and the modular REMUS 600 — Tehran is positioned to replicate that developmental trajectory beneath the water.
The captures have unfolded against a backdrop of President Donald Trump’s public boasts about American control of the Strait. Speaking in Chicago, Trump claimed oil prices were dropping and that the U.S. had taken “a record amount of oil out from the Hormuz Strait, more than we took out before the war”.
Yet as Trump boasted of American dominance, the IRGC Navy was pulling another piece of advanced American technology from the water — a quiet counterpoint to the public declarations of control.