Abstract Analytical solutions are obtained for the problem of boundary effects on the fully developed wake (or cavity) behind an inclined flat plate at an arbitrary angle of attack. The investigation is based on the Helmholtz free-streamline theory. Results are applied to four cases: (a) Blockage in a fixed-wall tunnel, (b) planing on a stream of finite depth, (c) planing toward a waterfall, and (d) flow over a flat plate in a bounded jet. Comparisons with linearized theory and available experimental data are made.