The structural design of wave energy harvesting devices play a crucial role in complex marine environments. To enhance output performance of triboelectric nanogenerator (TENG) in small-amplitude wave environments, this paper proposes a floating design method that utilizes wave energy converter (WEC) combined with elastic support coupled TENG based on boat design concepts. Using hydrodynamic model, the study investigates various types of WEC structures, resulting in maximum energy generation for the TENG. Additionally, the coupled TENG designed with elastic support demonstrates excellent performance in various experiments. The results indicate that the power density of the coupled TENG can reach 13 W/m³. Wave testing confirms that various floating structures significant differences in TENG output performance, and the boat-type float notably enhances the performance of TENG. The boat-type TENG exhibits an increase of 155% in open-circuit voltage, 414% in short-circuit current, and 218% in transferred charge for the interpolated electrodes, compared to the lowest square-type TENG. This work presents a novel approach for WEC design and improving energy conversion efficiency in large-scale ocean wave energy collection and accelerates the industrialization process of TENG in the field of marine engineering.