U.S. Navy Stages for Mine Clearance as Hormuz Blockade Begins
The U.S. Navy bet its mine countermeasures future on unmanned platforms. The Strait of Hormuz is now the first real-world test of that wager—and the early returns are sobering.
Bottom Line Up Front
The U.S. Navy's mine countermeasures force facing Iran's mined Strait of Hormuz in April 2026 is built almost entirely around unmanned platforms that have never been validated in a contested operational environment. The service retired its last purpose-built Avenger-class minesweepers from the Persian Gulf in September 2025 and shut down its MH-53E Sea Dragon airborne MCM detachment in August 2025, replacing both with an LCS-based mission package whose unmanned surface vehicles, unmanned underwater vehicles, and helicopter-borne sensors have been documented by the Navy's own training assessments as suffering from unreliable sonar recording, excessive pre-mission maintenance timelines, critical single-point mechanical failures, and inadequate sensor performance in turbid or deep water. Two legacy Avengers are being surged from Japan, but the force structure now confronting Iranian Maham-3 moored influence mines and Maham-7 bottom mines consists principally of three Independence-class LCS, 16 Expeditionary MCM companies operating Mk 18 Mod 2 Kingfish UUVs, a handful of Knifefish medium-class UUVs that have never operated outside controlled test environments, and Raytheon's Barracuda mine neutralizer—which completed its first untethered autonomous demonstration only nine months ago. The gap between the Navy's unmanned MCM ambitions and the reality of clearing a 100-nautical-mile strait against a dynamic, sensor-fused mine threat represents the most consequential mine warfare test since the 1991 Kuwait clearance operation.
The Operational Problem
On 11 April 2026, USS Frank E. Petersen Jr. (DDG-121) and USS Michael Murphy (DDG-112) became the first U.S. warships to transit the Strait of Hormuz since Operation Epic Fury began on 28 February, opening what U.S. Central Command described as the first phase of mine clearance operations. CENTCOM Commander Admiral Brad Cooper announced that forces would establish “a new passage” and share a verified safe corridor with commercial shipping. Additional forces, explicitly including underwater drones, would join the clearance effort within days.
The scope of the problem is staggering. The strait’s traffic separation scheme stretches roughly 100 nautical miles. As Captain Kevin Eyer, USN (Ret.), detailed in the April 2026 Proceedings, supporting both inbound and outbound oil and LNG traffic would require two Q-routes, each 2,000 yards wide, covering approximately 200 square miles of seabed that must be surveyed, classified, and declared safe. Before the war, the strait handled roughly 130 ships per day—approximately 20 percent of global seaborne oil and a comparable share of liquefied natural gas. In the first week of the blockade, fewer than a dozen ships transited without IRGC authorization.
U.S. intelligence, as reported by CBS News on 23 March 2026, estimated that Iran had deployed at least a dozen naval mines in the strait. These were identified as two types: the Maham-3, a moored influence mine weighing approximately 300 kilograms equipped with magnetic and acoustic sensors capable of engaging targets within about 10 feet; and the Maham-7, a 220-kilogram seabed bottom mine whose hull geometry was engineered to scatter incoming sonar waves, significantly complicating detection. According to the CAT-UXO (Collective Awareness to Unexploded Ordnance) database, the Maham-7 can be deployed by small craft or helicopters in water as shallow as 10 feet or as deep as 300 feet. The Defense Intelligence Agency estimated Iran’s total mine stockpile at more than 5,000 as of 2019, and CENTCOM assessments indicate Iran retains 80 to 90 percent of its small-boat and minelayer capacity.
Critically, reporting from multiple intelligence sources indicates that Iran itself may not have systematically tracked every mine placement—a product of IRGC Navy units operating fast attack boats capable of carrying two or three mines per sortie under combat conditions. This creates a problem qualitatively different from the 1991 Kuwait precedent: the minefield is not static. The IRGC Navy declared on 5 April that the strait would “never return to its previous status,” and evidence indicates mining may have continued even during the ceasefire.
What the Navy Retired
To understand the current MCM force structure, one must first understand what the Navy gave up. On 25 September 2025, the service held a final decommissioning ceremony in Bahrain for the last four forward-deployed Avenger-class MCM ships: USS Devastator (MCM-6), USS Sentry (MCM-3), USS Dextrous (MCM-13), and USS Gladiator (MCM-11). In January 2026—five weeks before Iran reportedly began mining the strait—those hulls were loaded aboard the heavy-lift vessel M/V Seaway Hawk and transported to Philadelphia for disposal.
The Avenger class represented 40 years of purpose-built mine warfare engineering. Their fiberglass-sheathed wooden hulls were specifically designed for minimal magnetic signature, enabling them to operate inside minefields where steel-hulled ships cannot safely go. They carried the AN/SQQ-32 mine-hunting sonar and the AN/SLQ-48 Mine Neutralization System, and their crews trained exclusively for mine warfare. The Navy has stated it has no plans to recommission any Avenger-class vessels.
Concurrently, the Navy’s MH-53E Sea Dragon detachment in the Arabian Gulf—the backbone of airborne MCM operations in the Fifth Fleet area for decades—was shut down in August 2025 as the platform was phased out. The service no longer maintains a dedicated heavy-lift airborne mine countermeasures capability in the region.
Four Avenger-class ships remain in Navy inventory, all forward-deployed to Sasebo, Japan. Two of those—USS Pioneer (MCM-9) and USS Chief (MCM-14)—were spotted departing Singapore westbound on 10–11 April, transiting the Strait of Malacca en route to CENTCOM. Their transit time to the Persian Gulf will be measured in weeks, not days.
The Unmanned Architecture
The replacement force structure rests on three pillars, each relying heavily on unmanned systems: the LCS MCM Mission Package, the Expeditionary MCM companies, and a developmental pipeline of next-generation unmanned vehicles. Each warrants detailed examination.
Pillar 1: The LCS MCM Mission Package
Three Independence-class LCS currently constitute the Navy’s primary MCM surface force in the region: USS Canberra (LCS-30), USS Tulsa (LCS-16), and USS Santa Barbara (LCS-32). Each carries the MCM Mission Package (MCM MP), which achieved Initial Operational Capability on 31 March 2023 aboard USS Cincinnati (LCS-20). The first operational packages deployed from San Diego in March 2025 aboard Canberra and Santa Barbara.
The MCM MP is a layered system designed to keep the manned ship outside the mine danger area while unmanned and airborne systems operate forward. Its principal components and vendors are:
The concept is elegant in theory: the ALMDS-equipped MH-60S sweeps the near-surface volume with laser imaging; the USV-towed AN/AQS-20C sonar hunts mines in the water column and on the bottom; the Knifefish UUV autonomously searches for buried mines in high-clutter environments; the UISS triggers influence mines; and the Barracuda neutralizes confirmed contacts. The LCS itself never enters the minefield.
The problem lies in execution. A Navy MCM Advanced Tactical Training brief—the final pre-deployment mine warfare assessment for LCS crews—documented systemic deficiencies that were reported by Hunterbrook Media in March 2026. Each Fleet-class USV mission required more than four hours of pre-mission maintenance followed by one and a half hours of GPS and sonar calibration. Multiple hunt missions were conducted where the AN/AQS-20 sonar failed to record data, a failure discoverable only during post-mission analysis. The USV exhibited a recurring tendency to “run away” beyond operator control, and its communications range required the LCS mothership to operate dangerously close to, or inside, the minefield—precisely the scenario the standoff architecture was designed to prevent.
Single points of failure compound the reliability issues. The platform lift moving equipment from the LCS mission bay to the flight deck is a critical node; its failure renders the helicopter combat-ineffective. If the USV tow hook breaks, the vehicle must be recovered by other means. If the Twin Boom Extensible Frame used to launch and recover USVs from the mission bay fails, the entire MCM platform is inoperable. Captain Scott B. Hattaway, Director of the SMWDC Mine Countermeasures Technical Division, acknowledged at the Combined Naval Event 2024 in the UK that the 11-meter USV’s form factor limits both the endurance and the towed sonar depth achievable by the AN/AQS-20C.
Navy doctrine further requires visual identification of mines before neutralization. The camera system on the USV reportedly fails even in relatively clear water, a significant limitation in the turbid conditions common in the Persian Gulf and Strait of Hormuz.
Pillar 2: Expeditionary MCM Companies
The Navy’s Explosive Ordnance Disposal community maintains 16 Expeditionary MCM (ExMCM) companies—27-person units composed of a command element, an unmanned systems platoon, an EOD MCM platoon, and a post-mission analysis cell. These companies have deployed extensively in the Middle East, with two continuously forward-deployed to Bahrain since 2014, and represent arguably the Navy’s most operationally proven MCM capability.
Each unmanned systems platoon operates 12 UUVs: six Mk 18 Mod 1 Swordfish (based on the Hydroid REMUS 100, approximately 80 pounds, 6–8 hour endurance, 100-meter max depth) and six Mk 18 Mod 2 Kingfish (based on the REMUS 600, approximately 800 pounds, 20–24 hour endurance, 600-meter max depth). Production of the Mk 18 Mod 2 was completed in 2023 after Hydroid, now a Huntington Ingalls Industries subsidiary acquired for $350 million in 2020, delivered more than 90 vehicles to the fleet.
The Kingfish uses side-scan sonar for search and discovery, Iridium satellite communications for over-the-horizon connectivity, and an autonomous navigation suite combining acoustic Doppler current profiler, inertial navigation, and P-code GPS. Crews launch and recover the UUVs from 11-meter rigid-hull inflatable boats or, in a field innovation developed by ExMCM operators in Bahrain, from a purpose-engineered rubber raft called the “Mallard” towed behind a Zodiac combat rubber raiding craft. The system can also deploy from a containerized “Stinger” launcher fitting a standard MilVan, enabling operation from virtually any vessel of opportunity.
The ExMCM companies are the Navy’s most flexible MCM asset—deployable by C-130 transport aircraft, operable from any port or platform, and staffed by EOD technicians who can visually identify and manually neutralize mines when unmanned systems reach their limits. Their principal limitation is throughput: clearing 200 square miles of seabed with RHIB-launched UUVs is a fundamentally slower process than operating from dedicated MCM ships.
Pillar 3: The Developmental Pipeline
Two significant unmanned systems are in development but are not yet fielded at scale for the Hormuz mission:
Knifefish Block 1 (General Dynamics Mission Systems). The Knifefish is the MCM MP’s dedicated subsurface mine-hunting UUV, purpose-built to detect buried and bottom mines in high-clutter environments using a low-frequency broadband synthetic aperture sonar with automated target-recognition software. Built on the Bluefin-21 platform, it is 21 inches in diameter, approximately 16 feet long, and weighs roughly 1,650 pounds. NAVSEA awarded General Dynamics a $44.6 million LRIP contract in 2019 after Milestone C approval, followed by a $72.8 million retrofit contract to upgrade five Block 0 systems to Block 1 configuration for deeper-depth operation and improved sensor performance. The Navy plans to procure 30 Knifefish systems (48 UUVs total)—24 for LCS and six for other vessels. However, as one analysis of the Hormuz deployment noted, the Knifefish’s April 2026 employment would represent its first use in a contested operational environment; whether its sonar can reliably classify a Maham-7 bottom mine against the acoustic clutter of the Hormuz seabed has not been validated outside controlled test settings.
Viperfish / Medium UUV (Leidos). The Viperfish is the designated successor to the Mk 18 Mod 2 Kingfish for ExMCM operations. In July 2022, the Navy awarded Leidos a $12 million design contract for the Medium Unmanned Undersea Vehicle, with options potentially reaching $358.5 million through 2032. In July 2023, Leidos received a $36.3 million contract modification to fabricate four engineering development models. Based on the L3Harris Iver4 900 UUV, Viperfish will combine mine countermeasures and submarine-based oceanographic sensing in a single modular platform, merging the requirements of the EOD community’s Kingfish replacement and the submarine community’s Razorback program. Leidos has described Viperfish as potentially “one of the most densely packed and technologically advanced underwater vehicles ever built,” but it remains in development and is not available for the current Hormuz operation.
Barracuda (Raytheon / RTX). The AN/WSQ-46 Barracuda mine neutralization vehicle represents the endgame of the unmanned MCM kill chain—an expendable, semi-autonomous UUV roughly the size of a sonobuoy that autonomously navigates to a mine contact, identifies it with onboard sensors, and detonates its warhead to destroy it. Raytheon won the initial $83.3 million design contract in April 2018, with options to $362.7 million. In July 2025, Raytheon successfully demonstrated Barracuda in its first untethered, semi-autonomous open-water operation in Narragansett Bay. The updated Barracuda will operate without a tether—a critical improvement over the original tethered concept. Its integration into the MCM MP is ongoing, with the system designed to be deployed from the Fleet-class USV.
The Force Protection Problem
Mine clearance is not merely a technical task; it is a combined-arms problem. MCM forces are inherently vulnerable because they must move slowly and methodically, focused on the water column and seabed, while exposed to aviation, drone, missile, and small-boat threats. The Strait of Hormuz places every MCM asset within range of Iran’s surviving arsenal of antiship cruise missiles, Shahed one-way attack drones, fast-attack boats, and shore-based launchers.
Admiral Daryl Caudle, the Chief of Naval Operations, addressed this directly in the April 2026 Proceedings: mine search and destruction is slow, deliberate work, and none of the Navy’s current MCM options performs well in a non-permissive environment. This reality explains CENTCOM’s decision to send two Arleigh Burke-class destroyers through the strait as the opening move—not to hunt mines, for which they carry no specialized equipment, but to establish local sea control and provide air and missile defense coverage for the MCM forces that will follow.
The USS George H.W. Bush (CVN-77) Carrier Strike Group, diverted around the Cape of Good Hope rather than risk the Red Sea Houthi threat, is transiting toward the theater. A-10 Warthogs have been conducting close air support operations over the strait, a choice that suggests CENTCOM judges the airspace sufficiently permissive for slow, non-stealthy aircraft—a prerequisite for MH-60S mine warfare helicopter operations.
Historical Context and the Scale of the Challenge
The 1991 Kuwait mine clearance operation is the closest historical benchmark. U.S. and coalition forces swept approximately 200 square miles of shallow water in 51 days—with a full squadron of Avenger-class ships, uncontested airspace, an enemy that had stopped mining weeks earlier, and precisely mapped mine locations. None of those conditions apply to Hormuz in April 2026.
The 1987–88 Tanker War offers a more cautionary parallel. During the first Earnest Will convoy on 24 July 1987, the reflagged tanker Bridgeton struck an Iranian M-08 moored mine immediately after transiting the Strait of Hormuz. No pre-cleared Q-routes existed; escort ships followed in Bridgeton’s wake, using the tanker itself as an improvised minesweeper. Nine months later, USS Samuel B. Roberts (FFG-58) struck another Iranian mine on 14 April 1988, suffering a 15-foot hull breach that broke the ship’s keel—triggering Operation Praying Mantis, the largest U.S. naval surface engagement since World War II.
The Washington Institute has estimated that clearing the Strait of Hormuz could require up to 16 MCM vessels. The Navy has seven—three LCS with MCM packages of unproven reliability and four Avengers, two of which are weeks away from the theater.
The Vendor Landscape
Assessment
The Navy’s transition to an unmanned-centric mine warfare force was conceptually sound. Keeping sailors out of minefields, extending sensor reach through autonomous platforms, and building a modular, deployable kill chain from detection through neutralization all represent genuine advances in mine warfare doctrine. The problem is not the vision but the execution timeline. The service retired proven, purpose-built platforms before their unmanned replacements had been validated in operationally relevant conditions.
The Knifefish has never operated against real mines in a contested environment. The Fleet-class USV’s reliability problems were documented by the Navy’s own training command. The Barracuda completed its first autonomous test nine months ago. The ALMDS excels in clear water against near-surface moored mines but cannot see bottom mines in turbid conditions. The AN/AQS-20C sonar, towed by a USV that requires six hours of preparation per mission, has exhibited data-recording failures that go undetected until post-mission analysis—meaning an entire sortie can be rendered useless without the crew knowing it.
Meanwhile, the ExMCM companies with their Mk 18 UUVs represent a proven, deployable capability—but one designed for expeditionary operations at harbor scale, not for clearing a 100-nautical-mile strait against a dynamic mine threat while under potential fire.
CENTCOM has structured the clearance effort in three phases: area securing, detailed survey with unmanned systems, and creation of a verified safe corridor for commercial shipping. The approach is doctrinally sound. Whether the unmanned systems are operationally ready to execute Phase 2 at the speed, scale, and reliability the mission demands is the question the Navy is about to answer under the most unforgiving conditions possible.
The Foreign Policy Research Institute and the April 2026 Proceedings have both noted that Belgium and the Netherlands jointly developed an advanced MCM capability—the rMCM program—centered on dedicated MCM vessels operating autonomous underwater and surface vehicles with high-definition synthetic aperture sonar. Neither nation has committed those assets to the strait. The broader lesson is clear: unmanned mine warfare is a coalition-wide gap, not merely an American one.
For the Navy, the Strait of Hormuz is now a live-fire examination of a force structure built on unmanned platforms. The systems will either prove their worth or expose a generational miscalculation in mine warfare investment. The 130 ships per day that once transited this chokepoint—carrying one-fifth of the world’s oil—are waiting for the answer.
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