US Navy FAQ hints at underreported Hormuz shipping attacks

The official count of attacks in the Strait of Hormuz represents a minimum, and a US Navy document may help explain why.

The agency responsible for the tally acknowledges it is incomplete. In its weekly report on 16 October, the UK Maritime Trade Operations centre (UKMTO) said it struggled to determine the actual number of incidents because most targeted vessels declined to report. That week, UKMTO recorded 12 attacks, ten inside the Strait, with one ship lost. It added that it knew of additional events from other sources but could not list them without verification.

For oil traders, this matters more than any single weekly figure. Freight rates, war-risk premiums and assessments of supply risk all rely on these figures. If most attacked vessels remain silent, the published number is a lower bound, not a measure.

Why ships might stay silent

Shipowners have clear commercial motives for keeping quiet, including insurance complications, flag state exposure and sensitivity about routing. But a less noticed document may also be a factor.

A US Navy FAQ for shipping companies, highlighted in a post on X by the account @angertab, explains how the Navy supports transits on the southern route of the Strait. It was issued by the Naval Cooperation and Guidance for Shipping (NCAGS) cell at US Naval Forces Central Command (NAVCENT), which coordinates with merchant vessels. Copies are posted on the Liberian ship registry’s website and on that of a Turkish shipowners’ and agents’ association.

The FAQ makes clear how limited that support is:

• The US provides airborne overwatch, intelligence and surveillance, and threat response, along with recommended waypoints and transit windows.
• The US does not deploy its own or allied vessels to escort ships, nor does it board them with personnel.
• Ships are instructed to disable AIS tracking, keep radar in standby mode and stay silent on VHF radio, as emissions could be used for targeting.
• When asked about operational security guidance for crew phones, social media and reporting restrictions, the Navy says best practices will be recommended but does not specify them.
• After the transit, the FAQ says no post-transit debrief is required.

This combination is key. A vessel told to go dark during transit and not asked to report afterward has little procedural incentive to file an incident report with UKMTO.

The FAQ does not instruct ships to stop reporting attacks. The reference to “reporting restrictions” appears in a question about phones and social media and could simply mean not broadcasting positions online. The document shows how silence could become the default but does not prove that silence is policy.

A corridor appearing riskier than portrayed

The FAQ also includes a reassurance that has not held up. It states that over 200 transits were completed with fewer than five successful attacks and no loss of life or vessels. According to the post, the file’s metadata dates it to 14 June, before Iran reimposed its blockade in mid-July.

The picture since then is very different. Reported UKMTO data shows that most projectile strikes since early July have hit the southern route, the corridor the US facilitates. October has brought the highest attack totals since the conflict began on 28 February. If this pattern is confirmed, the route offered as the safer option has become the primary target area, while the reporting that would reveal this is thinning out.

The post also says the file’s metadata points to an allied, non-US naval connection, suggesting the guidance passed through partner hands. investingLive has not verified this, and at most it shows who handled the file, not who wrote it.

What to monitor going forward

• UKMTO’s next weekly report: whether the share of unreported attacks grows and whether it breaks down incidents by route.
• NAVCENT or NCAGS: any clarification of what “reporting restrictions” covers or any updated guidance replacing the June figures.
• Insurance signals: war-risk premiums and any change to terms for southern-route transits, which would show if underwriters are pricing in the undercount.
• Tracked transits: gaps between AIS-visible traffic and US-stated transit figures, which already diverge because assisted ships run dark.

Practical implication: treat weekly Hormuz attack counts as a lower bound. When judging risk to Gulf supply, the direction of the numbers is more reliable than their level, and a quiet week in the data may not correspond to a calm week at sea.