A method and device for delivering multimedia data using IETF QoS protocols. The device may include a generally semi-flexible bi-parabolic membrane configured to deflect from an engaged position in which the device exerts pressure upon the user’s urethra, or a similar anatomical part. The rider runs on the beach behind the board to forwardly propel the board on the low friction surface of the shallow water. The methods, systems, and devices disclosed herein generally involve sizing the crossover passages, cylinders, or other components of a split-cycle engine or air hybrid split-cycle engine to improve efficiency.