A ‘system boundary’ is a theoretical concept in environmental science representing the intersecting and interrelated human and physical elements in the natural world at a given site. This chapter develops a system boundary discussion on surf sites, recognizing ‘surf system boundaries’ (Figure 2.1) as more than the beach and sea; they encompass numerous stakeholder interests and factors related to the scope of the ‘whole’ surf system as a sustainable and dynamic model. The following discussion serves to review and broaden the knowledge of surf system boundaries and provide clarity in two sets of dimensions: the physical boundaries of surf sites and the resource stakeholders.