Coaches’ beliefs about the nature of knowledge and knowing (their epistemic beliefs) are an integral but under-researched component in the development of a philosophy of coaching. The Theory of Integrated Domains in Epistemology (TIDE)1 offers a framework which may enhance the understanding of the development of coaches’ epistemic beliefs. The present study offers the first application of the TIDE framework to sports coaching. We present a case study of the nature and development of epistemic beliefs of a highly renowned Adventure Sports Coach (ASC), Doug Cooper, through the lens of the TIDE framework. Thematic analysis of a series of semi-structured interviews showed that early childhood experiences, strongly held beliefs about ASC as a domain of knowledge, and educational experiences in the later life were instrumental in shaping Doug's epistemic beliefs. We conclude that the TIDE framework has considerable potential for researchers and coach developers seeking to gain insight into and develop coaches’ beliefs