Portolan: The Living Chart of World Trade

⬅️ Back to Articles

Medieval sailors navigated with portolan charts: coastline-hugging maps studded with ports and rhumb lines, the most accurate picture of the known trading world at the time. Portolan picks that idea up and makes it live, a world map where trade flows move in real time, chokepoints glow with their current status, and a century of tariff policy sits one click underneath.

  1. The dataset underneath is substantial. Roughly 300 bilateral trade flows worth about $15 trillion in the 2024 reference year, 10 maritime chokepoints sized by the value passing through them, container ports sized by volume, plus sea lanes, air corridors, and rail bridges as separate layers.

  2. It refuses to sit still. A counter tallies how much world trade has crossed borders since you opened the page, at roughly $1.1 million per second against the WTO’s record 2025 total of $34.65 trillion in goods and commercial services. The latest tariff action, sourced live from the Federal Register, updates on its own.

  3. Chokepoints get a status board, which is the feature I keep coming back to. At this writing the Strait of Hormuz and Bab-el-Mandeb are marked disrupted; Suez and Panama are constrained. Click any gate and you see what actually moves through it, which turns vague news anxiety into specific geography.

  4. The tariff layer spans nearly a century, over 200 significant events from 1930 to 2026. Scroll it and recent history reads like a thriller: the Supreme Court ruling 6-3 in February that IEEPA does not authorize tariffs, the same-day Section 122 global surcharge replacing them, USTR reopening the fight through Section 301 investigations across dozens of economies, and the first-ever use of Section 338 to hit Canada with 50% duties, then suspending them.

  5. The map keeps its own caveats visible. The headline 5.9% average tariff covers 185 economies but is a simple average, not trade-weighted, so it runs above what the typical dollar of trade actually pays. Flows come from IMF IMTS and BACI, tariffs from World Bank effectively-applied rates, each labeled on screen. Most data products hide these footnotes; Portolan prints them next to the numbers.

  6. You might think a static textbook map already covers this. The difference is state. A printed map tells you Mexico sends the US $495 billion a year; Portolan shows you that flow in motion while Hormuz sits disrupted and a new Federal Register entry lands mid-session. Trade stops being a chapter and becomes weather, something with conditions you check.

  7. My honest caveat: it is a model, not a ledger. Three hundred curated corridors simplify thousands of real routes, and services trade mostly stays off-map beyond the headline counter. Use it to build intuition about structure and chokepoints, not to settle an invoice dispute.

The takeaway: Open Portolan during the next tariff headline instead of scrolling takes. Find the chokepoint or corridor the story touches, trace who actually ships through it, and read the 1930-to-2026 timeline around your event. Ten minutes of geography beats ten hot takes.

Related TMFNK Content

Crepi il lupo! 🐺