Since the 18th National Congress of the Communist Party of China, General Secretary Xi Jinping has attached great importance to the construction of a maritime power and has delivered important speeches on the maritime cause, emphasising that “building a maritime power is an important part of the cause of socialism with Chinese characteristics”. As China’s construction of a maritime power advances, the development of the maritime economy is also booming. The Guangdong-Hong Kong-Macao Greater Bay Area (GBA), as an important region for China’s construction of a maritime power, has regional advantages such as the highest degree of openness and the strongest economic vitality. While the GBA’s comprehensive strength has significantly increased, it has also presented more opportunities and challenges. Therefore, this paper analyses how China can use the GBA to develop the marine economy and makes suggestions for the future development of marine tourism in the GBA, which will help promote the prosperous development of the marine tourism economy.