This work investigates the fundamental techniques, ethics, and environmental considerations necessary for the practice of fly-fishing. Roderick L. Haig-Brown, a renowned conservationist and angler, utilizes his extensive experience in river ecosystems to provide a structured approach to the sport. The text serves as a foundational manual, balancing the mechanical requirements of casting and fly selection with the philosophical appreciation of the natural world.

The text is regarded as a classic instructional resource, valued for its clarity and the author's deep respect for the ecological context of angling. It remains a standard reference for those seeking to understand both the technical precision and the contemplative nature of the sport.