Each box is an axis-aligned bounding box in js/chokepoints.js. A hull is “in zone” when its latest AIS position falls inside that rectangle. That is a live count of tracked tankers (and, if you leave military pins on, type-35 hulls) — not barrels per day, not a customs series, and not a citation for historical average flow.
Do not copy the “avg flow” strings from the chokepoint panel into a new article or briefing as if OilRoutes measured them. For dated traffic figures, use the sourced notes on Hormuz and the Cape, and follow the named outlets those pages cite.
Strait of Hormuz
The only sea exit from the Persian Gulf into the Gulf of Oman. The map box sits over the narrows between Iran and the Musandam peninsula. Geography, EIA peacetime flow (not a panel string), partial pipeline bypasses, and why in-zone is not throughput are on the Strait of Hormuz oil chokepoint note. Sourced mid-August 2026 crossing counts belong on the Hormuz 2026 traffic note, not here.
Those mid-August 2026 Hormuz counts sit on the same crisis Armed Conflicts maintains for the strait — read the Hormuz crisis brief for the war context behind the AIS drop.
Suez Canal
The artificial cut from the Red Sea (via the Gulf of Suez) to the Mediterranean. The box covers the canal corridor rather than the whole Egyptian coast. When this waterway or the Red Sea approaches are constrained, some cargoes take the long way around Africa instead. Canal-corridor AIS versus SUMED throughput, VLCC lightening at Ain Sukhna / Sidi Kerir, and why in-zone is not a pipeline meter are on the Suez Canal and SUMED oil transit note.
Strait of Malacca
The passage between the Malay Peninsula and Sumatra that links the Andaman Sea / Indian Ocean to the South China Sea. The box is deliberately wide: the traffic lane is long, not a single pinch point like Hormuz. Volume leadership, Malaccamax as a draft ceiling, and why in-zone is not throughput are on the Strait of Malacca oil chokepoint note.
Bab-el-Mandeb
The southern gate between the Red Sea and the Gulf of Aden. Ships bound for Suez have to pass here. The box is small and sits on the strait itself. Geography, Yanbu, and the 2026 substitute chain are on the Bab el-Mandeb oil chokepoint note.
Turkish Straits
The Bosphorus and Dardanelles, which connect the Black Sea to the Sea of Marmara and then the Aegean. The box spans both straits rather than drawing two tiny rectangles. Why this trio stays on the map — and why in-zone is not EIA flow — is the secondary-straits glossary.
Panama Canal
The lock canal between the Caribbean / Atlantic and the Pacific. The box is tight around the canal prism. It is on the map because some product and crude cargoes use it; it is not a substitute for a canal-authority transit table. Lock-prism honesty and the products/LNG job are on the secondary-straits glossary.
Danish Straits
The passages (including the Great Belt and related waters) that connect the Baltic Sea to the North Sea / Kattegat. The box is a regional envelope, not a single named cut. Kiel as a partial alternative, and why a shadow-fleet headline is not this envelope, are on the secondary-straits glossary.
Cape of Good Hope
Not a narrow strait. It is the southern-Africa rounding that becomes a corridor when Suez, the Red Sea, or Hormuz is constrained. The box sits off the Cape. The 2026 detour record is on the Cape reroutes note.
How to use the boxes
Click a name in the header strip or open the chokepoint panel to fly the camera. Treat the number as “tracked AIS hulls in this rectangle right now.” It will change as messages arrive and as stale tracks are pruned. It is not a ranking of world oil chokepoints and not a forecast. How to read live AIS is the literacy note for boxes versus throughput and for dark AIS undercount. How a closed box becomes days, freight, and a crude risk premium — without inventing a dollar print — is the markets and freight note.