<p>Marine new quality productivity growth is strategically significant for promoting quality growth of the marine economy. The dynamic evolution, regional disparities, and obstacle factors of marine new quality productivity of coastal areas are comprehensively measured on the basis of statistical data from 2006 to 2021 of coastal areas in China. The entropy weight-TOPSIS method, kernel density estimation, Dagum Gini coefficient, and obstacle degree analysis are utilized. Results show that the marine new quality productivity of coastal areas in China has increased year by year, but regional growth is unbalanced. The regional disparities mainly originated from intergroup differences and hypervariable density. The results of kernel density estimation indicate considerable disparities and gradient effects in marine new quality productivity growth across coastal areas. In addition, marine innovation physical elements, marine innovation permeability elements, and marine resource utilization efficiency are important factors hindering productivity growth. Our findings facilitate an in-depth understanding of the marine new quality productivity growth in China’s coastal areas and balanced regional growth.</p>