This chapter explores how the maritime industry has transformed its technologies, national registries and labour resources over the past decades to serve the demands of globalisation. It looks at the global economic role of shipping, describing the marine transport system as a network of specialised vessels, the ports they visit, and transport infrastructure from factories to terminals to distribution centres to markets. The chapter presents maritime transport as a necessary complement to, and occasionally a substitute for, other modes of freight transport. For many commodities and trade routes, there is no direct substitute for waterborne commerce. On other routes, such as some coastwise or shortsea shipping or within inland river systems, marine transport may provide a substitute for roads and rail, depending upon cost, time and infrastructure constraints. The chapter traces maritime transformations in response to globalisation, from the shift of human labour (oars) to wind-driven sail, and the shift from sail to combustion. Two primary motivators for energy technology innovation – greater performance at lower cost – caused this conversion. It explores current maritime shipping activity to explain why ocean-going ships now have an activity level making them consume about 2% to 3% – and perhaps even as much as 4% – of world fossil fuels. The chapter examines future developments by extrapolating historical growth trends, and looking at scenario-based estimates.