This paper presents the mechanical design and modeling of an active segment of a bioinspired piezocomposite aquatic pump. The design and analysis is based on an electromechanical Euler-Bernoulli beam model. The self-contained propulsion/pumping system is composed of a series of piezo-active soft cymbal-like segments that are connected by passive soft films. By applying coordinated excitations for expansion and contraction to different active segments, the design creates a traveling wave along the pump axis, which in return propels the fluid to generate a unidirectional thrust force. In the model, the insulation and mechanical properties of the waterproofing sealant layer are considered. Using the proposed electromechanical model, a parametric analysis is conducted to understand the effectiveness of the cymbal-like piezocomposite active segment. Two performance metrics are considered, including the area change of the enclosed by the cymbal-like segment, and the work done by the actuators. The optimal structural parameters of the piezocomposite pump are decided by these performance metrics.