Major Sea Routes

Most of world trade moves by sea, and a handful of canals and straits carry a large share of it. These chokepoints are narrow, hard to replace, and heavily used, so a disruption at any one of them ripples through global supply chains. PortReckon lets you reroute around the three most consequential canals and straits to see how closing one changes the distance and ETA. This page explains what they are and why they matter.

Suez Canal

The Suez Canal links the Mediterranean Sea to the Red Sea, letting ships travel between Europe and Asia without sailing around Africa. It carries a large share of Asia-Europe container trade and Gulf oil bound for Europe. When it is unavailable, traffic diverts around the Cape of Good Hope at the southern tip of Africa, adding thousands of nautical miles and typically a week or more to the voyage. The 2021 grounding that blocked the canal for six days, and later diversions away from the southern Red Sea, both showed how quickly that reroute raises costs and delays worldwide.

Panama Canal

The Panama Canal connects the Atlantic and Pacific Oceans across Central America through a series of locks, and is central to trade between East Asia and the US East Coast as well as intra-American routes. Without it, ships must round Cape Horn or pass the Strait of Magellan at the southern end of South America - a far longer and rougher passage. The canal is also sensitive to drought: low water in Gatun Lake can force the authority to cut the number of daily transits and the maximum draft, effectively tightening the chokepoint even when it is open.

Strait of Hormuz

The Strait of Hormuz is the narrow entrance to the Persian Gulf and the single most important passage for seaborne oil and liquefied natural gas. Unlike the canals, it has no practical sea detour - the Gulf has only this one maritime exit - so any disruption there affects energy supply chains directly and is watched closely by markets.

Other key passages

Beyond the three you can toggle in the tool, several other waterways concentrate a great deal of traffic into a narrow lane:

• Strait of Malacca - the main link between the Indian and Pacific Oceans, funnelling much of the trade between the Middle East, South Asia, and East Asia past Singapore.
• Bab-el-Mandeb - the strait between the Red Sea and the Gulf of Aden; the southern gateway to the Suez route, so trouble here pushes ships onto the same Cape of Good Hope detour.
• Strait of Gibraltar - the narrow mouth of the Mediterranean and the meeting point of Atlantic and Mediterranean traffic.
• Turkish Straits (Bosphorus and Dardanelles) - the only sea route in and out of the Black Sea, important for grain and oil exports.
• Danish Straits - the passages linking the Baltic Sea to the North Sea, carrying northern European and Baltic trade.

Why the sea route is rarely a straight line

Because ships must follow water around continents and through these passages, the sea distance between two ports is usually well above the great-circle ("straight line") distance. Closing a chokepoint forces a longer detour, which is exactly what the reroute options let you measure. Terms like great-circle route and chokepoint are defined in the Glossary.

Trying it in PortReckon

Pick two ports whose route would normally use a canal - say a Europe-to-Asia pair for the Suez Canal, or an Atlantic-to-Pacific pair for Panama - and calculate the route. Then switch on the matching avoid option and recalculate: the route redraws around the closure, and you can compare the added distance and the longer ETA. To see how that extra distance turns into extra days, read How ETA Works. Results are for planning and visualization only.

Routes are for planning/visualization only and are not certified for navigation.

This website is provided "as is", for general information and planning only, with no warranty of accuracy, completeness, or fitness for any purpose. To the fullest extent permitted by law, the operators of this website accept no responsibility or liability for any loss, damage, cost, or decision arising from use of the site or reliance on its routes, distances, or ETA estimates. Use at your own risk.