Windward: One Week Into the Ceasefire — Hormuz Remains Active But Not Open

Windward has published a comprehensive first-week analysis of the Iran ceasefire's impact on maritime operations in the Strait of Hormuz, and the central finding is unambiguous: the ceasefire did not produce normalisation. It produced a more complex maritime regime where access remained controlled, movement continued selectively, and trade flows stayed constrained even as U.S. enforcement expanded. As of mid-April, 823 vessels remain present across the Gulf, including 91 dark fleet vessels and 89 China-owned or operated ships. The key commercial signal is not how many vessels transited the Strait, but which ones did. Throughout the ceasefire week, the cohort remained dominated by sanctioned, falsely flagged, Iran-linked, or risk-tolerant vessels. No blue-chip operators returned. Vessels turned around before and after transit, slowed to unusually low speeds, drifted in holding patterns, or continued under constrained routing along Iranian-controlled corridors. Transit volumes rose — from 11 vessels on April 7 to 21 on April 12 — but participation remained narrow and behaviour remained fragmented. Iranian exports remain structurally resilient: Since March 1, total departures from Kharg Island have reached approximately 58.75 million barrels, with more than 90% directed toward China. By April 13, total Iranian oil-on-water stood at approximately 157.7 million barrels. Satellite imagery confirmed active loading at Kharg throughout the ceasefire, including VLCCs spoofing their positions and reporting false destinations. U.S. blockade enforcement: The U.S. Navy began enforcing a blockade of Iranian ports on April 13, with OFAC announcing a new sanctions package targeting shadow fleet infrastructure on April 15. At least 10 vessels were turned back in the first days of enforcement, but sanctioned and falsely flagged vessels continued to test the limits of enforcement in real time. Why this matters for ship managers: The Hormuz situation is the most significant ongoing test of AI maritime domain awareness capability in commercial shipping. Windward's ability to track AIS manipulation, dark fleet activity, sanctions evasion, and spoofing behaviour vessel-by-vessel is providing intelligence that conventional market sources cannot match. For fleet operators trading anywhere near the Gulf, the question is whether your risk assessment and routing decisions are informed by this level of intelligence — or whether you are operating on delayed, incomplete information. On Our Radar follow-up: Our Hormuz AI Intelligence tracking item predicted that P&I clubs and war risk underwriters would begin requiring evidence of AI-assisted route risk assessment. The U.S. blockade enforcement phase makes that prediction more urgent. [Windward Blog]

This story is part of the Maritime AI Digest of 19 April 2026.