A phenomenology of the bodily experience of interactive flow adds to Csikszentmihalyi's flow theory. Whereas Csikszentmihalyi attended to teachers' and students' experiences of flow separately, this inquiry explores flow through three water-inspired layers of physical interaction between fitness professionals and their clients. Teaching fitness is likened to the emotive experience of surfing the ocean peaks, swimming in the shallows, and diving deep beneath the surface. As a producer of high, immersed, and deep flow, this teaching moves actively from an elevated stage of one-sided instruction to motions of deep, other-directed absorption. Learning to teach in this flow-producing way is portrayed through first-person accounts of the intensification of closeness, connection, reciprocity, and mutuality between fitness professionals and their clients. This study, with its reference to the postures, positions, gestures, and expressions of fitness instruction, indicates a kinaesthetic register of flow consciousness that serves as a guide to effective exercise pedagogy. (Contains 8 endnotes.)