To be an island, Taiwan owns an abundant ocean environment, therefore, it is good to develop varied marine activities. Keel-boat is one of the important activities just budding from the branch. Our study explored the development of keel-boat activity in Taiwan, following with an analysis framework of four-function development, i.e., leisure, sports, education, and industry. Methods of case study and qualitative skills, such as interviews, documentary analysis, and observation were used in this study, including applying on varied actors, i.e., governmental units, NGOs, business, and individuals. Data was analyzed under the four-function framework and some results had been produced as the following: 1. Leisure and sports are dominant functions of keel-boat activity in the post development. However, leisure should be the future developing direction. 2. The actors in private sector play an important role to promote keel-boat leisure. 3. Some regulations needed to be changed for the development of keel-boat activity.