The wave loads and motion responses of an Unmanned Surface Vehicle (USV) in water will directly influence the powering requirement, energy supply design and function of the installed sensors. In the present article, to investigate the wave loads and motions response characteristics of a USV advancing on the free surface, a Higher-Order Rankine Source (HORS) method is proposed. During the discretization of the boundary elements, bi-quadratic B-splines are applied to distribute the velocity potentials on the body surface and free surface. Based on the proposed HORS method, steady state simulation and time-domain simulation approaches are both used for predicting the wave loads and motion responses of a novel Small Waterplane Area (SWA) USV in calm water and regular waves, respectively. The predicted wave loads in calm water and the predicted heave and pitch in heading wave are compared with corresponding model test data. The good agreement found indicates the validity of the proposed HORS method. Finally, the heave and pitch motion responses and the wave components of the USV including diffraction and radiation forces and Froude−Krylov forces are investigated when the SWA USV is running against heading wave under different conditions of wavelength, wave steepness and advancing velocity.

水面无人艇（USV）在水中的波浪载荷和运动响应将直接影响动力需求、供电设计和所安装传感器的功能。在本文中，为了研究自由水面上前进的USV的波浪载荷和运动响应特性，提出了一种高阶朗肯源（HORS）方法。在边界元离散化过程中，应用双二次 B 样条将速度势分布在物体表面和自由表面上。基于所提出的 HORS 方法，稳态仿真和时域仿真方法分别用于预测新型小水线面面积 (SWA) USV 在平静水域和规则波浪中的波浪载荷和运动响应。将预测的静水波浪载荷和预测的艏向波浪升沉和纵摇与相应的模型试验数据进行了比较。所发现的良好一致性表明了所提出的 HORS 方法的有效性。最后，研究了SWA USV在不同波长、波陡度和前进速度条件下逆航向波行驶时的升沉和俯仰运动响应以及USV的波浪分量，包括衍射力、辐射力和Froude-Krylov力。