U.S. Military Guidance Reveals High-Risk Reality of Hormuz's 'Southern Highway'

As Washington and Tehran move toward implementing a memorandum of understanding aimed at ending months of conflict, a newly circulated U.S. military document is offering the clearest picture yet of the extraordinary measures that have kept at least some commercial shipping moving through the Strait of Hormuz amid one of the most dangerous security environments in recent maritime history.

The undated FAQ, distributed to maritime industry partners, details procedures for transiting what the U.S. military calls the "Deep South Route"—an emergency corridor running south of the Strait's traditional Traffic Separation Scheme through Omani territorial waters.

The route appears to correspond to what President Donald Trump called the "Southern Highway" when he announced that ships were once again moving through the Strait on Monday.

"Ships are starting to move, many loaded up with Oil, out of the Strait of Hormuz," Trump wrote on Truth Social. "They are going along the Southern 'Highway,' which is totally safe, secure, and pristine."

The military's own guidance is more far more restrained about the risk environment. "Threats are presented regularly," the FAQ states.

While the document says the "overwhelming majority" of threats have been defeated by U.S. and partner forces, it cautions that military units may not always be able to provide real-time warning to vessels because they are focused first on defeating threats.

"There have been over 200 successful transits with less than five completed attacks, none resulting in loss of life or vessel," the document says.

The risks of the route were on display over the weekend when a commercial tanker was struck by an unidentified projectile near the southeastern approaches to the Strait of Hormuz while transiting waters associated with the U.S.-coordinated corridor.

According to UK Maritime Trade Operations (UKMTO), the vessel was hit approximately six nautical miles east of Oman. The crew was safe, there was no pollution and the ship continued its voyage.

The incident occurred just hours after U.S. Central Command announced it had intercepted multiple Iranian one-way attack drones targeting commercial shipping in the area.

Neither CENTCOM nor UKMTO linked the incidents, and the nature of the projectile that struck the tanker remains unknown. Nevertheless, the attack appeared to be the first publicly reported case of a vessel being hit while operating along the U.S.-facilitated route.

The FAQ shows that such risks were well understood, and offers a rare window into the operating environment that emerged during the Strait of Hormuz crisis, describing a system in which commercial vessels transit under U.S. military overwatch while actively minimizing their electronic signature and navigating a threat environment where attacks have remained a persistent concern.

Those measures include turning off AIS, minimizing radar emissions, limiting radio transmissions and conducting transits at night whenever possible.

"It is recommended that AIS be turned off," the guidance states. Radar should remain in standby mode. VHF silence is recommended, and vessels are encouraged to minimize radio frequency emissions that could potentially be used for targeting.

The procedures echo guidance first reported by gCaptain earlier this month after INTERTANKO informed members of a U.S.-coordinated transit system through Omani waters. That advisory described vessels transiting at night, in groups rather than convoys, with close coordination with U.S. naval authorities.

The FAQ provides additional details. Unlike the escorted convoys used during previous Gulf crises, ships using the route are not accompanied by naval vessels. Instead, the military describes its role as "a combination of airborne overwatch, ISR, and threat response."

The document also establishes strict eligibility requirements. Ships whose last or next port of call is Iran are prohibited from participating, as are sanctioned vessels and members of the so-called dark fleet.

Notably, the Deep South Route leaves the final decision to shipowners and masters. The FAQ makes clear that no U.S. military personnel are embarked aboard merchant vessels and participation in the facilitated transit program is voluntary. Vessel operators remain free to withdraw at any time or decline a transit altogether if they determine the risks are too great.

That distinction is important. While U.S. forces provide airborne overwatch, intelligence, surveillance and threat response, merchant ships are still responsible for navigating the Strait on their own—often at night and with reduced electronic signatures—in one of the world's most heavily militarized waterways.

The FAQ surfaced as maritime security assessments have begun to improve following the announcement of a U.S.-Iran Memorandum of Understanding.

In its latest advisory issued Tuesday, the Joint Maritime Information Center (JMIC) lowered the regional threat level from SEVERE to SUBSTANTIAL, saying the agreement had contributed to a more stable operating environment.

Even so, JMIC warned that "an attack is a strong possibility" in the Strait of Hormuz and Gulf of Oman.

Traffic also remains a fraction of normal levels.

"Strait of Hormuz traffic remained significantly reduced, with commercial vessels continuing to route south of the TSS via Omani territorial waters," JMIC said.

The Strait historically handles around 138 vessel transits per day. According to JMIC, there were no commercial transits on June 14 and only seven on June 15.

The advisory also warned that mine threats remain present within and near the traditional Traffic Separation Scheme and that recurring GNSS interference continues across the region.

Meanwhile, blockade enforcement remains in force. "Merchant vessels continued to report a strong multinational naval presence," JMIC said. "Blockade enforcement remained active, with vessels subject to verification hails and direction from U.S. units."

Ships were advised to "clearly demonstrate non-Iran-bound intentions until further notice."

Taken together, the documents provide a striking picture of how commercial shipping has adapted to one of the most significant disruptions in modern maritime history.

The Strait of Hormuz may be edging toward stability, but for now many ships continue to avoid the traditional shipping lanes, sail south along the Omani coast with AIS switched off, and rely on military protection while navigating what remains an extraordinary security environment.

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Fuente: GCAPTAIN_NEWS