Underwater acoustic analysis is widely used in naval architecture, where structural vibration and sound propagation are coupled through pressure exchange at the fluid–structure interface. This study develops a numerical model of two-way fluid–structure interaction (FSI) framework based on the high order mesh/meshfree methods. The vibration of plate on the ship hull is modeled by reproducing kernel particle method (RKPM) to deal with complex geometry and to simplify the discretization. The high order RKPM shape functions can also offer better description of high frequency vibration of structure. Surface displacement and normal velocity in frequency-domain are then obtained and prescribed as boundary conditions for the acoustic problem. The fluid acoustics domain is governed by the Helmholtz equation in the frequency domain and solved using Isogeometric analysis (IGA). IGA represents geometry and field variables with the same basis and employs higher-order NURBS for accurate approximation. Sound sources can be simply modeled using monopoles and dipoles, while quadrupole effects are neglected under a low-Mach-number assumption. Because monopoles and dipoles are singular point sources, a weak-form IGA formulation rewrites point-source terms via global integration into expressions involving shape functions and their derivatives. Interface coupling enforces continuity of normal motion and action–reaction force consistency, enabling pressure feedback to update the structural response. Recently , our tank acoustic simulations were performed and showed good agreement with COMSOL. This study is then applied to solve vibration-induced underwater noise, and to develop a high accuracy tool for evaluating characteristics of ship underwater acoustics.