Some commercial ship captains are seeking Houthi email clearance before transiting the Red Sea, despite maritime security authorities warning vessels against contacting the group’s coordination office.

The requests are handled by the Humanitarian Operations Coordination Center (HOCC), which Yemen’s Houthis established in 2024 to communicate shipping restrictions, issue warnings and process transit applications.

According to an investigation published by The Wall Street Journal on 6 November 2026, correspondence between ship captains and the HOCC shows that some shipping companies have sought assurances from the Houthis before navigating the Red Sea and Bab el-Mandeb Strait.

The practice has attracted attention since the Houthis declared a maritime blockade against Saudi Arabia on 20 July 2026. The group subsequently warned shipping companies against loading or discharging cargo at Saudi ports and threatened action against vessels violating its restrictions.

Reuters reported that two tankers carrying Saudi crude to Asian destinations reversed course in the Red Sea following the warnings.

Although vessels without connections to Israel, the United States or the United Kingdom have generally not been required by the Houthis to seek clearance, some operators have contacted the HOCC as an additional precaution amid the expanded restrictions.

One documented case involved the Chinese container ship Zhong Cheng Chang Ling, whose captain submitted a transit request identifying the vessel as Chinese-owned, managed and operated, with a Chinese crew.

The captain also declared that the vessel had no links to Israel, the United States or the United Kingdom and would comply with the International Regulations for Preventing Collisions at Sea (COLREGs).

In September 2026, the HOCC replied with a limited-period clearance for passage through the Red Sea, Bab el-Mandeb Strait, Gulf of Aden and Arabian Sea.

The response instructed the vessel to keep its Automatic Identification System (AIS) and VHF Channel 16 operational, follow established shipping routes and report suspicious activities. The crew was also asked to notify the HOCC of changes to the voyage.

According to vessel-tracking information cited in the original investigation, Zhong Cheng Chang Ling changed its AIS destination field from Port Klang, Malaysia, to “armed guard on board” on 8 September.

The vessel subsequently transited the Bab el-Mandeb Strait and entered the Indian Ocean on 11 September, when its AIS destination field was changed back to Port Klang. The AIS entry did not independently establish whether armed guards were physically aboard.

The captain told the newspaper that the ship’s management company had instructed him to contact the Houthis as an additional precaution.

However, the HOCC process is not recognized as a legitimate maritime transit authorization system by international maritime authorities.

Yemen’s Maritime Affairs Authority in Aden has warned ship operators against engaging with the HOCC, citing potential legal, sanctions and security risks. The authority instead recommends using recognized maritime security reporting channels, including United Kingdom Maritime Trade Operations (UKMTO) and the Maritime Security Centre – Indian Ocean (MSCIO).

The US Maritime Administration’s current Red Sea security advisory, issued on 23 September 2026, warns that vessels with Israeli, American, British or Saudi associations face heightened risks from Houthi attacks.

The advisory recommends that US-flagged vessels assess the security implications of AIS transmissions and permits masters to switch off AIS when its continued operation could compromise vessel safety or security.

It also recommends coordinating voyage planning with recognized naval security organizations and reporting incidents through established maritime security channels.

The contrasting approaches highlight the difficulties facing ship operators navigating the Red Sea, where some companies seek assurances from the Houthis while recognized maritime security authorities advise against engaging with the group’s coordination system.

A Houthi-issued clearance does not constitute internationally recognized permission to navigate the waterway or guarantee protection against attack.