This work presents a robust control system for a twin hull-based unmanned surface vehicle, named EDSON-J, which is being built at the Universidad Nacional de San Agustín de Arequipa and whose main mission is the autonomous monitoring of ocean water quality and lagoons vulnerable to heavy metal contamination. The vehicle has been designed to carry additional payload consisting of electronic instrumentation destined to measure the water conditions in real time. This paper focuses on the control design of controllers for an unmanned surface vehicle with mass as parameter varying. The approach used is the linear parameter-varying control (LPV control); its goal is to synthesize a controller that guarantees robust stability and performance of the system despite the presence of parameter varying, disturbances and sensor noise. The simulation results, in frequency domain and time domain, show an improvement in the LPV robust control approach in comparison with LTI/H∞ controllers.