What is the world's busiest ocean for shipping?

The Atlantic on the traditional measure of routes and crossings, though the Pacific now carries more container traffic by volume - the answer has shifted with manufacturing, and the trans-Pacific route between East Asia and North America is now the single largest flow of goods anywhere.

What matters more than the ocean is the chokepoints. Roughly a third of the world's container traffic goes through the South China Sea, a large share of its oil through the Strait of Hormuz, and about twelve per cent of global trade through the Suez Canal - which is why the Ever Given wedging itself across the canal for six days in 2021 held up an estimated ten billion dollars of goods a day, and why traffic diverting around the Cape from 2023 added roughly ten days and considerable cost to Asia-Europe voyages.

The whole system is invisible until it stops. Around ninety per cent of world trade goes by sea, in ships crewed by perhaps twenty people carrying twenty thousand containers, and the industry is regulated through flags of convenience that let an owner in one country register in another and crew from a third. The pandemic was the first time in decades that most people noticed shipping existed, when hundreds of thousands of seafarers were stranded aboard past the end of their contracts because no port would let them ashore.