This short paper explores the link between maritime commerce and key macroeconomic indicators, such as gross domestic product (GDP) and international trade. We introduce a new metric derived from near-real-time satellite imagery of ports and processed using deep learning techniques. The index captures the scale of ongoing maritime activity and is tested for its ability to nowcast economic indicators and forecast shifts in European GDP, imports, and exports. Results show that the index closely tracks real economic activity, particularly GDP, well before official data releases. This provides a valuable tool for policymakers to make timely and informed decisions.