<p>Marine new-quality productivity is the key driver of China’s high-quality marine economic growth. Based on the three-dimensional reconfiguration of ‘knowledgeable laborers, intelligent labor materials, and high-valued labor objects’, this study defines its core connotation. We selected 11 coastal province-level regions in China from 2010 to 2023 to assess the development level of marine new-quality productivity and examined its spatiotemporal evolution from an economic geography perspective. The main findings are as follows: First, during the study period, the marine new-quality productivity in China’s coastal areas remained in nascent stages of development but with a steady upward trend. The development levels of all components also maintained positive growth. Furthermore, the spatial pattern of ‘eastern marine economic circle &gt; northern marine economic circle &gt; southern marine economic circle’ remains largely stable, while regional imbalances are still prominent. Finally, the development of marine new-quality productivity is a slow process with a strong and stable level distribution, which tends to transfer upward. The Chinese case study offers valuable insights into the development of marine economies in other regions worldwide.</p>