Hormuz and the limits of the index.

What market indices can tell you, and what they cannot.

The UNCTAD Strait of Hormuz Dashboard launched 28 April 2026 aggregates the market signal clearly. The Baltic Dirty Tanker Index stands at 2,795, against a 2024 average of 1,091. VLSFO bunker in Singapore has risen from a 2024 average of $571 per tonne to $1,076. Brent crude has traded above $120 on intraday peaks. These are the right numbers to watch. They confirm severity. They do not distribute it.

An accumulation underwriter pricing a P&I book, a crude desk managing a supply position, or a lender stress-testing a Capesize fleet facility needs something the index cannot provide: which specific counterparties carry Hormuz exposure, for which commodity, at what percentage of their total seaborne supply, and what the genuine cost of each rerouting option is at current market rates. Aggregate indices are inputs to that question. Run it through The Narrows and you get the answer.

Who is exposed, for what commodity, and at what percentage of supply.

The Narrows model produces bilateral dependency figures at the (importer, chokepoint, commodity) level. The table below shows Hormuz dependency for the commodity classes that account for the majority of the Strait's commercial traffic volume. These are not estimates of aggregate throughput. They are specific bilateral percentages: the share of each importer's total seaborne supply of each commodity that transits Hormuz, drawn from 2023 UN Comtrade bilateral data.

What continuation costs at current market rates, for specific importers.

Market indices give a real-time aggregate read on disruption severity. The Narrows model translates that severity into bilateral cost for specific counterparties across four time horizons and two toll-level scenarios. The figures below use Japan as the primary example because Japan carries the highest absolute Hormuz exposure of any single importer across both LNG and crude petroleum. The model runs the same analysis for any importer and any commodity combination.

All rerouting costs are recalculated at current market rates: VLSFO at $1,076 per tonne and tanker charter rates consistent with the BDTI at 2,795. These are approximately 1.9x and 2.5x their respective 2024 baselines. The cost of disruption at current market conditions is materially higher than any pre-crisis model assumption.

What each option costs, vessel class by vessel class, at current market rates.

The following costs apply to future voyages and forward supply chain decisions, not to vessels already committed to Gulf loading. A laden VLCC inside the Persian Gulf has no exit alternative. These figures represent the cost premium facing importers who can reorganise sourcing toward non-Gulf origins, and the toll threshold at which doing so becomes commercially rational for new fixtures. Costs are recalculated at current market conditions: VLSFO at $1,076 per tonne and charter rates consistent with the live BDTI reading.

The asymmetry between crude and LNG is the defining structural feature of Hormuz risk, but the framing matters. For vessels already in the Gulf, both crude and LNG face identical binary exposure. The distinction emerges in the forward supply chain response: crude importers have a costly but real sourcing alternative in non-Gulf origins. LNG importers do not. Any Hormuz disruption affecting Gulf LNG exports produces a supply gap that the market cannot fill through alternative sourcing, regardless of price or timeframe.

LNG is the IMO bridge fuel. The bridge runs through Hormuz.

IMO's revised GHG Strategy targets net-zero emissions from international shipping by 2050. Carbon Intensity Indicator regulations, effective from 2023, have pushed operators toward LNG as the primary compliant fuel available at scale for deep-sea voyages. LNG-fuelled vessels now represent over 40% of new deep-sea tonnage ordered. This energy transition creates a second-order Hormuz dependency that is not visible in the standard chokepoint exposure model.

As the global fleet converts to LNG propulsion, the nature of Hormuz exposure changes. It is no longer only a cargo risk for energy-importing nations. It becomes a propulsion risk for the fleet itself. A sustained Hormuz disruption simultaneously reduces LNG cargo supply and restricts the fuel supply for vessels designed to run on LNG. These two effects compound: the ships most affected by cargo disruption are increasingly the same ships that require LNG to operate.

What the Narrows model adds that market data cannot provide.

The UNCTAD Hormuz Dashboard provides an excellent real-time read on market-level disruption. The Narrows Chokepoint Dependency Model operates at a different analytical layer: bilateral, commodity-specific, and scenario-driven. The two tools are complementary. The dashboard gives you the aggregate signal. The model shows which counterparty carries the exposure.

The model assumptions are substitutable. Charter rates, bunker prices, disruption duration, and toll level are all variable inputs. A counterparty running their own scenario can replace the model's default vessel-class rates with their own book rates and rerun the exposure calculation in real time. This is the capability that aggregate market data, however current, cannot replicate.