Taiwan is surrounded by ocean with national scenic areas, bathing beaches, scenic spots and areas for tourists and the environment has good potentiality for developing ocean leisure activities and sports. The objective of this research is to study the relationships among scuba divers' enduring involvement, environmental knowledge and environmental behavior. This study hypothesizes that scuba divers' enduring involvement positively impacts environmental knowledge; enduring involvement positively impacts environmental behavior; and environmental knowledge positively impacts environmental behavior. This study uses Penghu as research areas. The plan is to interview around 400 Scuba Divers. The research results are expected to provide information to the government to promote scuba diving.