On a clear morning in the Strait of Hormuz, a loaded tanker has roughly 12 minutes of warning before a fast-attack boat launched from an Iranian coastal base can close to weapons range. The boat is small enough to vanish in sea clutter on commercial radar, fast enough to outrun most escort responses, and cheap enough that Iran fields them by the dozen. Since the regional conflict escalated in late 2025, vessels like these have been at the center of a campaign that U.S. government advisories now attribute directly to Tehran.
According to incident tallies compiled by defense analysts tracking the conflict, Iranian fast-attack craft have struck at least 26 commercial ships in and around the strait. U.S. Navy officers involved in escort operations have described the boats as among the hardest targets they face in the waterway, a characterization echoed in multiple defense press briefings and consistent with decades of American naval doctrine on asymmetric threats in confined waters. The figures and descriptions draw on aggregated reporting from outlets including the U.S. Maritime Administration (MARAD), CENTCOM public affairs statements, and open-source maritime tracking; official U.S. incident logs remain classified.
What MARAD is telling ship operators
MARAD advisory 2026-004, issued to the commercial shipping sector, names Iran as the source of attacks on merchant vessels and identifies the weapons involved: anti-ship missiles, unmanned aerial vehicles, and unmanned surface vessels. The advisory covers the Persian Gulf, the Strait of Hormuz, and the Gulf of Oman, and it provides reporting procedures for crews who come under attack or observe suspicious activity. It is not a vague caution about “regional instability.” It is a direct, state-level attribution from the U.S. government, and it carries policy weight for insurers, flag states, and port authorities worldwide.
A companion advisory, 2026-001A, goes further. It warns of possible retaliatory strikes by Iranian forces and instructs vessel operators to maintain contact with the Naval Cooperation and Guidance for Shipping (NCAGS) team under U.S. Naval Forces Central Command (NAVCENT). Operators are also told to monitor advisories from the United Kingdom Maritime Trade Operations center and the Joint Maritime Information Center. Together, the two documents amount to a crisis-level information architecture: the U.S. military expects more attacks and wants every commercial ship in the zone plugged into its warning network.
For shipping companies, compliance is not optional in any practical sense. A tanker that fails to check in with NCAGS or ignores updated routing guidance is sailing without the only safety net available in waters where the next threat could come from a missile, a drone, or a crewed speedboat armed with rockets and riding low in the waves.
Why fast-attack boats are so difficult to stop
Iran’s Islamic Revolutionary Guard Corps Navy (IRGCN) operates a fleet of small, fast craft purpose-built for hit-and-run warfare in shallow, congested waters. The inventory includes Boghammar-type gunboats, C-14 catamarans capable of speeds above 50 knots, and Peykaap-class missile boats that can carry anti-ship weapons despite displacing only a few tons. These are not improvised fishing skiffs. They are military platforms designed around a specific operational concept: close the distance before the enemy can react, strike, and withdraw into coastal clutter or Iranian territorial waters.
In the Strait of Hormuz, geography works in their favor. The navigable channel narrows to roughly two miles in places, and commercial ships following the Traffic Separation Scheme are predictable in course and speed. A loaded very large crude carrier (VLCC) making 12 knots through the strait cannot maneuver to evade a boat doing four times its speed. Radar returns from small fiberglass hulls blend with wave returns, especially in the choppy conditions common in the strait. By the time a bridge watch identifies an inbound contact as hostile, the engagement window for any defensive response has already shrunk to seconds.
Swarm tactics compound the problem. Rather than sending a single boat, IRGCN doctrine calls for coordinated approaches from multiple vectors, forcing a defending ship or escort to divide its attention. U.S. Navy surface combatants carry weapons and sensors that can handle the threat, but even a guided-missile destroyer cannot be everywhere at once in a strait that handles roughly 21 percent of the world’s petroleum consumption daily, according to the U.S. Energy Information Administration.
Historical pattern and current escalation
Iran’s use of fast-attack boats against commercial shipping is not new. During the 1980s Tanker War, Revolutionary Guard speedboats struck dozens of merchant vessels in the Persian Gulf, prompting the U.S. Navy’s Operation Earnest Will convoy escort mission. In 2019, the IRGCN seized the British-flagged tanker Stena Impero in the strait, and limpet mine attacks on tankers near the Gulf of Oman were attributed to Iran by the United States, the United Kingdom, and Saudi Arabia. Tehran denied involvement.
The current campaign differs in scale and in the directness of U.S. attribution. MARAD’s advisories leave no ambiguity: the U.S. government holds Iran responsible. The 26-ship tally reported by defense analysts, while not confirmed vessel by vessel in declassified documents, is consistent with the tempo of incidents tracked by commercial maritime security firms and with the frequency of MARAD and UKMTO alerts issued since late 2025.
War-risk insurance premiums for vessels transiting the strait have climbed sharply. Lloyd’s Market Association Joint War Committee listings now include expanded areas of the Persian Gulf and Gulf of Oman, and underwriters are pricing additional premiums that can add hundreds of thousands of dollars to a single voyage. Some operators have rerouted cargoes around the Cape of Good Hope, adding weeks and millions in fuel costs. Others continue to transit, calculating that the premium is cheaper than the alternative, but doing so with armed security teams and heightened bridge watches.
What remains unconfirmed
Several important details are not yet established in publicly available primary sources. MARAD’s advisories describe the threat environment and attribute attack methods to Iran, but they do not publish a running count of individual incidents or damage assessments. The 26-ship figure circulating in defense reporting appears to originate from aggregated secondary accounts rather than from an official U.S. government incident log released to the public.
The precise command-and-control structure behind the fast-attack boat operations also remains opaque. Open-source reporting generally attributes the boats to the IRGCN rather than Iran’s conventional navy (IRIN), but MARAD’s advisories stop short of naming specific units or commanders. Whether individual attacks are centrally ordered from Tehran or initiated under broad standing guidance by local IRGCN commanders is an open question, though for a tanker captain in the strait the distinction is academic.
Iran’s strategic intent is similarly debated. Some analysts argue that the fast-attack boat campaign is calibrated to raise costs for Western-aligned shipping without crossing a threshold that would trigger a large-scale military response. Others see it as part of a broader effort to demonstrate that Iran can hold global energy markets at risk if its own interests are threatened. Neither interpretation is confirmed in any declassified U.S. assessment. Both are consistent with Iran’s long record of asymmetric strategy in the Gulf.
What this means for ships, markets, and the next move
For commercial operators, the practical guidance is straightforward even if the strategic picture is not. MARAD’s advisories represent the minimum baseline for risk planning. Companies should assume that the missile, drone, and unmanned-vessel capabilities Iran has demonstrated are complemented by crewed fast-attack boats operating at close range, and that these tools may be used together. Maintaining contact with NCAGS, monitoring UKMTO and JMIC feeds, and following prescribed routing and reporting procedures are the most concrete steps available.
For the U.S. Navy and allied forces, the fast-attack boat problem is a resource equation with no comfortable answer. Escorting every tanker through the strait would require a sustained commitment of surface combatants that competes with other global demands. Destroying the boats preemptively risks escalation. Tolerating periodic strikes on commercial shipping erodes deterrence and drives up costs that ultimately flow through to energy consumers worldwide.
Roughly one-fifth of the world’s oil passes through the Strait of Hormuz every day. A single successful attack on a loaded VLCC could send crude prices spiking within hours. Twenty-six strikes, if the aggregated count holds, suggest that Iran has already demonstrated both the capability and the willingness to use these boats at a pace that tests the limits of naval protection. In a waterway this consequential, the smallest platforms on the water are producing the largest strategic headaches, and neither side shows signs of backing down as of June 2026.
More from Morning Overview
*This article was researched with the help of AI, with human editors creating the final content.
