Skip to content
Iran Conflict 2026
6MAR

136 navigation denial zones in Gulf

4 min read
04:48UTC

Windward maritime analytics identified 92 AIS denial zones and 44 GPS jamming areas blanketing the Persian Gulf — making the world's most important oil transit route electronically unnavigable.

← Back to Iran loses half its navy; China eyes HormuzJump to analysis ↓
ConflictDeveloping
Key takeaway

At 136 combined electronic warfare zones, the Gulf's maritime information environment has been systematically degraded to a level that transforms accidental navigation errors into potential diplomatic or military incidents — and that directly undermines the AIS-based mechanism China is relying on to protect its own vessels.

Windward, the maritime analytics firm, identified 92 AIS denial zones and 44 GPS jamming zones across the Persian Gulf on 5 March — 136 areas where the electronic systems that keep commercial shipping safe have been deliberately disabled.

The Automatic Identification System is mandated by the International Maritime Organisation under the SOLAS convention for all vessels over 300 gross tonnes on international voyages. It broadcasts vessel identity, position, course, and speed to other ships and shore-based traffic management. GPS provides the positional data that feeds AIS and underpins all modern navigation. In the Strait of Hormuz — roughly 21 nautical miles wide at its narrowest, with designated shipping lanes only two miles wide in each direction — loss of either system creates immediate collision and grounding risks. Approximately 20,000 seafarers and 15,000 cruise passengers remain stranded in these waters , unable to navigate safely out of the area even if insurance and military conditions permitted transit.

The jamming introduces a specific problem for the one arrangement that has produced a physical transit result. China's separate Hormuz passage arrangement relies on vessels broadcasting Chinese ownership credentials via AIS — the vessel referred to as Iron Maiden completed its transit precisely this way. AIS denial zones make that identification mechanism unreliable. If Iranian electronic warfare cannot distinguish a Chinese-flagged tanker from a Western-flagged one inside a denial zone, the safe passage arrangement depends on coordination that the electronic warfare environment actively undermines. Iran's own remaining naval assets lose the ability to identify friendly traffic in the fog its own forces have created.

Iran has demonstrated electronic navigation denial capabilities before — Iranian officials attributed the 2011 capture of a US RQ-170 Sentinel drone to GPS spoofing, and Iran has deployed electronic warfare systems along its Gulf coast for over a decade. The 136 denial zones Windward documented represent a systematic blanketing of Gulf waters, adding a layer of physical navigational danger on top of the insurance withdrawal that has already halted commercial traffic . Each compounding layer raises the threshold for resumption of shipping. Even a Ceasefire would not immediately restore safe navigation; electronic warfare infrastructure would need to be stood down, zones verified clear, and insurers convinced — a process measured in weeks, not hours.

Deep Analysis

In plain English

Ships crossing the Gulf use two systems to stay safe: AIS, a radio beacon that broadcasts a ship's identity and position to other vessels and port authorities, and GPS for precise positioning. When AIS is blocked, other ships cannot track you electronically; when GPS is jammed, your own instruments may give a wrong position. With 92 zones where AIS does not work and 44 where GPS is unreliable, vessels in the world's most militarily active waterway are navigating partially blind. This dramatically raises the risk of collision, of accidentally entering restricted waters, and of being seized — any of which can be presented as a hostile act. It also creates a specific problem for China's arrangement with Iran: China's deal to protect its ships relies on those ships broadcasting Chinese ownership over AIS, but Iran's own jamming makes that broadcast unreliable.

Deep Analysis
Synthesis

There is a direct operational contradiction between events 25 and 15. China's safe-passage arrangement relies on Chinese vessels broadcasting ownership credentials over AIS — but Iran's own 92 AIS denial zones suppress the very signal that identifies protected Chinese ships. If no technical exemption exists (and none has been reported), Iran's electronic warfare posture is inadvertently threatening the diplomatic arrangement it is simultaneously negotiating with Beijing. A Chinese vessel misidentified or unseen in a denial zone represents a potential Chinese-Iranian incident that could collapse the commercial arrangement both parties are trying to maintain.

Root Causes

Iran developed indigenous GPS spoofing capability as early as 2011 (the RQ-170 Sentinel drone incident) precisely because it cannot contest US naval dominance through conventional platforms. Maritime electronic warfare is one of the few asymmetric domains where Iran can impose costs without direct kinetic engagement. The structural driver is now acute: with more than 30 surface vessels destroyed, Iran's conventional maritime capability is critically degraded, making electronic denial its primary remaining lever in Gulf waters.

Escalation

Ninety-two AIS denial zones is an order of magnitude above routine peacetime electronic warfare activity in the Gulf, indicating Iran has activated a comprehensive maritime denial posture rather than selective disruption. This level of EW saturation makes unintentional incidents — vessels straying into restricted waters, missed identification signals — statistically likely rather than merely possible, with each incident carrying escalation potential.

What could happen next?
2 risk2 consequence1 precedent
  • Risk

    GPS-degraded navigation at this scale makes non-hostile maritime incidents — collisions, inadvertent territorial water violations — statistically probable rather than merely possible, each carrying escalation potential.

    Immediate · Assessed
  • Consequence

    War risk insurance premiums for Gulf transits are rising sharply, transmitting conflict costs to global energy consumers through cargo pricing.

    Short term · Assessed
  • Risk

    Iran's AIS suppression directly undermines the China-Iran safe-passage arrangement if Chinese vessels cannot reliably broadcast identifying credentials inside denial zones, risking a Chinese-Iranian incident that collapses the diplomatic deal.

    Short term · Suggested
  • Precedent

    A 136-zone electronic warfare environment establishes a template for maritime area denial that non-US naval powers will study and replicate in future conflicts where conventional surface fleet engagement is not viable.

    Long term · Assessed
  • Consequence

    UKMTO and NAVCENT's ability to issue actionable navigational warnings is overwhelmed at this zone density, effectively degrading the international maritime safety notification system for the duration of the conflict.

    Immediate · Suggested
Sources:Windward
Mentions:VLCC →US Fifth Fleet →Persian Gulf →US Navy →China →UKMTO →National Security Council (Iran) →Ceasefire →Iran →Strait of Hormuz →Windward →
First Reported In

Update #23 · Iran loses half its navy; China eyes Hormuz

Windward· 6 Mar 2026
Read original →
Different Perspectives
South Korean financial markets
South Korean financial markets
South Korea, which imports virtually all its crude oil, is absorbing the war's economic transmission most acutely among non-belligerents. The second KOSPI circuit breaker in four sessions — with Samsung down over 10% and SK Hynix down 12.3% — reflects an industrial economy unable to reprice energy costs that have risen 72% in ten days. The market response indicates Korean industry cannot sustain oil above $100 per barrel without margin compression across manufacturing, semiconductors, and shipping.
Migrant worker communities in the Gulf
Migrant worker communities in the Gulf
The first confirmed civilian deaths in Saudi Arabia — one Indian and one Bangladeshi killed, twelve Bangladeshis wounded — fell on communities with no voice in the military decisions that placed them in harm's way. Migrant workers live near military installations because that housing is affordable, not by choice. Bangladesh and India face the dilemma of needing to protect nationals who cannot easily leave a war zone while depending on Gulf remittances that fund a substantial share of their domestic economies.
Azerbaijan — President Ilham Aliyev
Azerbaijan — President Ilham Aliyev
Aliyev treats the Nakhchivan strikes as a direct act of war against Azerbaijani sovereignty, placing armed forces on full combat readiness and demanding an Iranian explanation. The response is calibrated to maximise international sympathy while stopping short of military retaliation — Baku cannot fight Iran alone and needs either Turkish or NATO backing to credibly deter further strikes.
Oil-importing nations (Japan, South Korea, India)
Oil-importing nations (Japan, South Korea, India)
The Hormuz closure is an existential threat. Japan, South Korea, and India receive the majority of their crude through the strait — they will bear the heaviest economic cost of a war they had no part in.
Global South governments (Indonesia, Brazil, South Africa)
Global South governments (Indonesia, Brazil, South Africa)
Neutrality was possible when the targets were military. 148 dead schoolgirls made it impossible — no government can explain that away to its own citizens.
Turkey
Turkey
Has absorbed three Iranian ballistic missile interceptions since 4 March without invoking NATO Article 5 consultation. Each incident narrows Ankara's political room to continue absorbing without Alliance-level response.