What Is Maritime Shipping and Why Does It Matter?

The Invisible Backbone of Modern Commerce

Right now, roughly 60,000 merchant vessels are crossing the world's oceans. They carry crude oil from the Persian Gulf to refineries in Houston. They haul wheat from the Black Sea ports of Ukraine to flour mills in Cairo. They transport iPhones from Shenzhen to Long Beach in steel boxes stacked twelve stories high. Maritime shipping is the single largest physical system that human civilization has ever built, and almost nobody thinks about it until something goes wrong.

The math is stark. According to the United Nations Conference on Trade and Development (UNCTAD), roughly 80 to 90 percent of global trade by volume travels by sea. By value, the figure sits around 70 percent, since high-value goods like electronics and pharmaceuticals sometimes fly cargo instead. But for the raw materials that feed and fuel civilization -- iron ore, coal, grain, petroleum, natural gas, fertilizer -- there is no alternative. Pipelines work for some oil and gas routes, but they are geographically fixed. Rail and road freight handle domestic distribution. Only ships can move tens of thousands of tons across 10,000 miles of open water at a cost per unit that makes global trade economically viable.

The cost of moving goods by sea is extraordinarily low per unit. Shipping a 40-foot container of electronics from Shanghai to Rotterdam -- a journey of roughly 10,000 nautical miles -- costs somewhere between $1,500 and $4,000 under normal market conditions. That container can hold about 8,000 pairs of shoes, which means the ocean transport cost per pair is less than 50 cents. This is why global supply chains exist. Without cheap shipping, it would not make economic sense to manufacture goods in one hemisphere and sell them in another.

The Fleet: Four Types of Ships That Move the World

The global merchant fleet is not a uniform mass of generic cargo boats. It consists of highly specialized vessel types, each designed for a specific category of trade. Understanding these categories is essential because disruptions affect each differently, and each carries a different basket of goods to consumers.

Container Ships

Container ships carry manufactured goods in standardized steel boxes called TEUs (twenty-foot equivalent units). A modern Ultra Large Container Vessel (ULCV) like the MSC Irina can carry over 24,000 TEUs -- enough to hold 240 million pairs of shoes or 48 million laptops. These ships are the backbone of consumer trade. Nearly everything you buy at a retail store that was not grown or mined domestically arrived in a container: furniture, clothing, appliances, electronics, auto parts, toys, medical devices.

The container shipping market is dominated by a handful of carriers -- the World Shipping Council tracks the top 15 -- operating through three major alliances that control over 80 percent of capacity on East-West trade routes. This concentration means that when a disruption forces rerouting or delays, the effects ripple through the entire network quickly. There is no slack capacity waiting in reserve. The system runs tight by design, because idle ships lose money.

Oil Tankers

The tanker fleet carries crude oil and refined petroleum products. Tankers are classified by deadweight tonnage (DWT): Very Large Crude Carriers (VLCCs) haul 200,000 to 320,000 DWT, Suezmax tankers fit the Suez Canal at 120,000 to 200,000 DWT, and Aframax tankers (80,000 to 120,000 DWT) handle shorter regional routes. About 60 percent of the world's seaborne oil trade passes through just two chokepoints: the Strait of Hormuz at the mouth of the Persian Gulf and the Strait of Malacca between Malaysia and Indonesia.

When tanker routes are disrupted, the effects move fast. Oil markets are priced globally in real time. A closure of Hormuz -- through which roughly 20 percent of the world's daily oil supply transits -- would spike crude prices within hours and show up at American gas pumps within two to three weeks. No other shipping disruption produces consumer price effects with that speed.

Bulk Carriers

Bulk carriers transport unpackaged dry commodities in their massive holds: iron ore, coal, grain, bauxite, phosphate, cement. These are the workhorses of heavy industry. A single Capesize bulker -- too large for either the Suez or Panama Canals -- can carry 180,000 tons of iron ore from Brazil to China in a single voyage. The Baltic Dry Index (BDI), which measures dry bulk freight rates, is closely watched by economists as a proxy for raw-material demand and, by extension, global industrial activity.

Bulk cargo is less time-sensitive than container goods, but it matters enormously for food prices. About 500 million tons of grain moves by sea each year. When Russia's invasion of Ukraine disrupted Black Sea grain shipments in 2022, wheat futures spiked 50 percent in two weeks, and bread prices rose across Africa, the Middle East, and South Asia -- regions that depend on imported grain for basic nutrition.

LNG Carriers

Liquefied natural gas (LNG) carriers are among the most technically sophisticated ships afloat. They transport natural gas cooled to minus 162 degrees Celsius, compressed to 1/600th of its gaseous volume, in insulated spherical or membrane tanks. Global LNG trade has surged over the past decade as countries from Japan to Germany shift away from coal and piped gas toward more flexible supply. Qatar, Australia, and the United States are the three largest LNG exporters. All of Qatar's exports -- and Qatar is the world's single largest source -- transit the Strait of Hormuz.

The Routes: Where the World's Goods Travel

Maritime trade follows a small number of dominant routes, shaped by geography, canal infrastructure, and the location of production and consumption centers. The three most important trade lanes are:

Asia to Europe -- the longest major container route, running roughly 11,000 nautical miles from Shanghai or Shenzhen through the Strait of Malacca, across the Indian Ocean, through the Suez Canal and the Mediterranean to ports like Rotterdam, Hamburg, and Felixstowe. This route carries manufactured goods westbound and European machinery, chemicals, and luxury goods eastbound. When Houthi forces began attacking commercial shipping in the Red Sea in late 2023, this entire trade lane shifted: carriers rerouted south around the Cape of Good Hope, adding 10 to 14 days to transit times and roughly $1 million in fuel costs per voyage.

Asia to North America (Transpacific) -- the highest-value container route in the world. Goods manufactured in China, Vietnam, South Korea, and Japan cross the Pacific to West Coast ports (Los Angeles, Long Beach, Seattle-Tacoma) or transit the Panama Canal to East Coast ports (Savannah, New York/New Jersey, Houston). This route carried over $1.2 trillion worth of goods into the United States in 2024.

The Persian Gulf to Asia and Europe -- the world's most important energy corridor. Crude oil, refined products, and LNG flow through the Strait of Hormuz to refineries and power plants in China, India, Japan, South Korea, and Europe. Roughly 21 million barrels per day of crude oil pass through Hormuz, accounting for about one-fifth of global liquid fuel consumption.

These three lanes, plus the grain routes from the Black Sea and the Americas, account for the vast majority of seaborne trade value. They also share a common vulnerability: each passes through at least one narrow chokepoint where geography, politics, or climate can bring traffic to a halt. Risk and Route monitors five such chokepoints in real time.

How Shipping Costs Become Consumer Prices

The connection between ocean freight rates and the price you pay at checkout is real but indirect. It works through three channels, each operating on a different time lag.

Direct transport costs. When container rates rise, importers pay more to move goods. Some absorb the increase through reduced margins; others pass it forward. During the COVID-19 supply chain crisis of 2021-2022, container rates on the Shanghai-to-Los Angeles route jumped from roughly $1,500 to over $20,000 per FEU (forty-foot equivalent unit). The IMF estimated that this surge added approximately 1.5 percentage points to consumer inflation in importing countries, with a lag of roughly 12 months.

Energy input costs. Higher crude oil and LNG prices, driven by tanker disruptions, increase the cost of transportation fuel, electricity, fertilizer (natural gas is the primary input for ammonia-based fertilizer), and plastics. These costs propagate through every stage of production and distribution. A sustained $20 increase in the price of a barrel of crude oil adds roughly 45 to 50 cents per gallon to U.S. gasoline prices within three weeks.

Agricultural commodity prices. Grain, oilseeds, and fertilizer all move by ship. When bulk carrier routes are disrupted, the cost of raw agricultural inputs rises, which pushes up farm-gate prices, which pushes up wholesale food prices, which eventually reaches the supermarket shelf. This chain is slower -- typically 60 to 120 days from disruption to checkout -- but it affects the most politically sensitive category of consumer spending: food.

Why Disruptions Matter More Than They Used To

Global supply chains have become leaner, longer, and more concentrated over the past three decades. Just-in-time manufacturing, pioneered by Toyota in the 1970s and adopted across industries by the 2000s, reduced inventory buffers to a minimum. A factory that once kept 90 days of parts on hand now keeps 15. A retailer that once warehoused two months of stock now relies on continuous replenishment from ships that arrive on precise schedules.

This efficiency is genuine. It reduces warehousing costs, frees up capital, and lowers the price of finished goods. But it comes at the cost of resilience. When a container ship runs aground in the Suez Canal, or when missile strikes force the entire Red Sea corridor offline, or when drought restricts Panama Canal transits, there is no surplus capacity to absorb the shock. The system is optimized for normal conditions, and normal conditions are becoming less frequent.

The International Maritime Organization (IMO) now classifies climate risk, geopolitical conflict, and pandemic recurrence as structural threats to maritime trade -- not temporary anomalies. Between 2020 and 2026, the shipping industry has experienced the COVID port congestion crisis, the Ever Given blockage, the Red Sea rerouting, the Panama Canal drought restrictions, and escalating tensions around the Strait of Hormuz. Each of these events individually would have been called a "black swan" a decade ago. Collectively, they represent a new baseline of disruption.

This is why Risk and Route exists. Not to track ships for the sake of tracking ships, but to measure how these disruptions transmit into the prices that matter to households, businesses, and policymakers -- and to provide that signal before it arrives at the checkout counter.