Why is sea freight cheaper than air freight?

From an economic perspective, the transportation cost of sea freight is relatively low. Maritime transportation relies on large cargo ships and vessels, which have a huge cargo capacity and can transport large amounts of goods at once. Due to economies of scale, the transportation cost per unit of goods will be relatively low in the case of large quantities of goods. In contrast, air transportation relies on airplanes for transportation, with limited cargo capacity and higher transportation costs. In addition, the fuel cost of sea transportation is relatively low because the fuel consumption rate of ships is usually lower than that of airplanes.
Secondly, technological factors are also an important reason why sea freight is cheaper than air freight. With the continuous development of shipping technology, modern cargo ships and vessels have made significant progress in design, materials, power, and other aspects, greatly improving transportation efficiency while reducing transportation costs. In addition, the maintenance and upkeep costs of ships are relatively low, further reducing the overall cost of sea transportation. In contrast, aircraft manufacturing and maintenance costs are higher, and require more technical support and personnel investment.
Furthermore, the scale effect of sea transportation is also a key factor leading to its price advantage. Due to the large volume of sea transportation, goods can share more fixed costs, such as ship procurement, maintenance, insurance, and other expenses. This reduces the transportation cost per unit of goods, thereby improving the competitiveness of sea transportation. In contrast, air transportation has a relatively lower fixed cost allocation due to its smaller transportation volume, resulting in higher transportation costs per unit of goods.
In addition, sea transportation also has a longer transportation time, which is also one aspect of its price advantage. Although air freight has a significant advantage in speed, it also means higher transportation costs. Although sea freight takes a long time, it can meet the transportation needs of some goods with low time requirements. For some goods that are not in a hurry to deliver, choosing sea freight can save a lot of transportation costs.
Meanwhile, maritime transportation also has certain advantages in terms of coverage and accessibility. Sea freight can cover various ports worldwide, and both developed and developing countries can transport goods through sea freight. This makes sea transportation an indispensable part of international trade. Although air transportation is faster, it may be limited in coverage, especially for some remote areas or small airports.
The main reasons why sea freight is cheaper than air freight include economy, technology, economies of scale, transportation time, as well as coverage and accessibility. These factors work together to give maritime transportation a significant cost advantage. However, this does not mean that sea freight is the best choice in all cases. When choosing a transportation method, it is necessary to comprehensively consider multiple factors such as the nature of the goods, delivery time, transportation cost, and destination. Air freight may be more suitable for goods that are tight on time, have higher value, or have smaller volumes. For some goods that do not require high time, have a large quantity or volume, choosing sea freight may be more cost-effective.