The Persian Gulf, a vital corridor for global energy and trade, is increasingly affected by a sophisticated threat to maritime safety: the manipulation and disruption of Automatic Identification System signals. Since mid-2025, numerous vessels have reported incidents of AIS spoofing and GPS jamming, with ships falsely appearing to have called at ports in sanctioned jurisdictions. This has raised serious compliance concerns and undermined navigational safety.

These developments coincide with rising regional tensions, where recent military activity and retaliatory actions have intensified the risk environment – particularly around strategic chokepoints like the Strait of Hormuz.

AIS and GPS systems face two major types of interference: jamming and spoofing.

Jamming works by overwhelming a GPS receiver with high‑powered signals, effectively blocking its ability to function. Spoofing, on the other hand, is more insidious – it feeds the receiver false data, tricking it into displaying an incorrect location or time.

While once primarily a military tactic, spoofing is now also used in civilian contexts, and the threat to maritime navigation is growing. A vessel misled by spoofed GPS data may inadvertently sail off course, risking collisions, groundings, and other potentially severe accidents.

Regulatory and advisory responses

Maritime (and governmental) authorities have urged member states to implement protective measures and enhance monitoring capabilities. Flag states have issued advisories recommending the use of alternative navigation methods and increased vigilance.

The US Department of Transportation Maritime Administration (US MARAD) published an advisory in April 2025, which remains relevant: 2025-006 Worldwide-Foreign Adversarial Technological, Physical and Cyber Influence.

Insurers and industry bodies have also responded, encouraging operators to maintain accurate voyage records and prepare for potential disruptions in electronic navigation systems.

Commercial and legal implications

AIS spoofing in the Persian Gulf presents significant challenges for commercial shipping operations, particularly in relation to sanctions compliance. When vessel positions are falsified to appear as if they have called at ports in sanctioned jurisdictions, such as Iran, it can trigger scrutiny from financial institutions, insurers, and regulatory authorities. This may lead to delays in cargo release, payment disruptions, or reputational damage for shipowners and charterers.

The manipulation of AIS data also complicates due diligence processes, as stakeholders may struggle to verify the legitimacy of voyage histories.

Although spoofing and jamming attempts by warfare systems are highly sophisticated and coordinated, several resilience and countermeasures can be taken by merchant vessels to allow for better recognition and protection.

Loss prevention guidance

Management company

Issue clear navigational and security guidance

• Provide the vessels with recommended routing guidance for the Persian Gulf and ensure each vessel has received an updated threat assessment before entry, incorporating both cyber threats of jamming and spoofing, in addition to geopolitical risks.
• Consider alternative means to protect the antennas onboard to prevent jamming/spoofing, which may be applicable for your vessel.

Provision with regional intelligence

• After the initial threat assessment, continuously monitor and distribute the intelligence on jamming/spoofing and regional military/ naval and suspicious activities to the ship.

CSO cooperation

• Maintain close communication with the Ship Security Officer (SSO) to ensure security measures are understood and implemented onboard.
• Consider requesting the vessel to implement heightened security measures – while staying compliant with flag required MARSEC level.

Availability and support

• Provide immediate technical, operational, legal and insurance-related assistance should it be required.

Vessel

Prepare a voyage security risk assessment

• With the intelligence provided by the company, create a detailed voyage security risk assessment before entering the Persian Gulf, including the risk of GPS jamming and AIS spoofing.
• Ensure that the entire bridge team is familiar with the mitigation measures on the risk assessment.
• Clearly communicate the risk of jamming and spoofing to the entire crew, emphasising the importance of manual position verification.

Frequent verification of vessel position

• Position shall, as a matter of navigational routine, be checked and reaffirmed by all available means at hand to ensure that electronic navigation systems are within accuracy / not compromised.
• Document the verification routine in the appropriate navigational log.

Maintain situational awareness

• Keep updated on current maritime security alerts and regional threat assessments from recognised sources such as UKMTO and JMIC.
• Establish continuous lookout and monitoring of suspicious activities when transiting the area.

Contingency planning – loss of electronic navigation

• Discuss and perform drills on contingency plans for loss of GPS, ECDIS and other navigational data integrity – as applicable for your vessel.
• Assign specific duties to bridge and engine room teams in various contingency scenarios.

Incident reporting

• Immediately report any signs of jamming/spoofing or any other suspicious activity to company CSO/DPA, UKMTO and flag states as required.
• Maintain accurate records for post-incident reporting.