The ocean is a natural extension of the terrestrial area through the river basin. In the marine development activities, the production links of marine fishing, maritime transportation, marine mineral development, and mariculture are jointly completed in the sea areas and watersheds; while the sea salt industry and seawater utilization are completely in All production links are completed on land. In addition, the development of modern science and technology promotes the advancement of marine science and technology, the development of marine industry, the development of marine high-tech and the emergence of new products, also promotes the advancement of science and technology in the river basin and the development of related industries. Products are developed interactively through this technological extension. The text is intended to explain:. ['Dependence of the marine economy on the spatial distribution of the basin economy.', 'The development of modern technology has promoted the progress of the sea and land economy.', 'Marine economy and river basin economy are industrially intertwined.', 'The development of modern technology has promoted the convergence of sea and land economies.']