Marine education aims to educate a citizenry capable of making astute decisions about the impact of human activities, and encourage ecologically sensitive practices. Coral reefs are critically important, and are in serious decline. This research explores high school students' reef experiences with respect to specific learning outcomes. Queensland students were surveyed and interviewed after training in the classroom and at Great Barrier Reef sites. Both quantitative and qualitative methods were employed. I analyse changes in the Marine Education Society of Australasia's Three A's of Coastal and Marine Studies for senior high school students. This presupposes learning where a gain in knowledge (awareness) leads to a change in attitude, and thereby improves personal actions toward marine environments. This research analyses whether the links between the variables are linear and effects of reef experience. The student participants were divided into groups receiving different educational interventions. Some students received both interventions, while others received only one treatment and a contrast group received neither. Pre- and post-test survey questionnaires and interviews collected responses, and results were compared. This research contributes a Model of Ecological Intention to Act, which was developed and tested as part of the research process. Results show reef experiential education to have a positive effect on students' environmental knowledge (awareness), attitudes towards reef environments and stated intention to act. The reef experience alone caused the greatest change in environmental attitudes and ecological intention to act. This alludes to the fact that knowledge itself could be slowing down the improvement of attitudes and intention to act. In my study students' initial environmental scores were found to be low, and the relationship was not linear. An interdisciplinary methodology for addressing pedagogical questions in marine education was developed that provides baseline information for future research. Past research reveals more about environmental knowledge and attitudes than about students' educational experience and preferences. An attempt to advance the understanding of learning in marine experiential education was made by addressing the idea of moving away from linear learning models. This study identifies issues and challenges, and supplies a focus on adolescent learners, and their experiences. This work took an elemental step in addressing the question of proximal relations between humans and coral reefs. The analysis generated statistical findings, while student accounts confirmed the learning value of structured underwater activities. It is time for us to rethink curricular practice, issues of sustainability and education in the 21st century. Appended are: (1) Extended List of Acknowledgments; (2) Copy of Initial Survey Questionnaire: Pre-Test; (3) Final Survey Questionnaire; (4) JCU Ethics Approval; (5) Commission for Children and Young Children Approval Letter; (6) Education Queensland Approval Letter; (7) Letter of Approval to the University Ethics Committee; (8) Sample School Approval Letter; (9) Sample Student Parent Approval Letter; (10) Sample Student Parent Approval and Waiver Form; (11) Snorkel & Dive Risk Management Plan; (12) Medical Emergency Contact List of Health Care Practitioners; (13) Researcher Structured Interview Questions; (14) List of Peer Interview Structured Questions; (15) Coral Reef Monitoring Underwater Data Collection Sheet; (16) Coral Reef Monitoring Methodology; (17) The Southern Cross Catholic College Field-Trip to Northwest Island; and (18) CU Snorkel Protocol. (Contains 35 tables, 42 figures, and 18 color photographs.) [Ph.D. Thesis, James Cook University.]