The recently proposed underwater acoustic (UWA) orthogonal time frequency space (OTFS) communication has been recognized as a promising technology due to its Superior simulation performance. To verify the feasibility and robustness of the UWA-OTFS system in the real UWA channel, a field experiment plan was proposed in this paper. Considering the large delay and Doppler effect, practical structures of the transmitter and receiver are provided in detail. In order to satisfy the condition of synchronization and Doppler compensation, a block packet frame is described. Finally, the compressive sensing theory and the minimum mean square error (MMSE) criterion are leveraged for channel estimation and equalization, respectively. The designed experiment was constructed in the Guishan Island Sea area on January 9, 2024. The results demonstrate that the proposed UWA-OTFS system is effective in practical UWA scenarios and outperforms the UWA-OFDM system in terms of the bit error rate (BER).