Modern underwater unmanned vehicle must operate in unpredictable conditions of water environment. This leads to a problem of motion control systems with uncertain parameters development. The paper is dedicated to development of robust motion control system for an underwater remotely operated vehicle. Several issues of developing control systems with parametric uncertainty were considered: deriving a mathematical model of an underwater remotely operated vehicle with interval parametric uncertainty, estimation of interval parameters values, developing a structure of motion control system and synthesizing a set of robust controllers, providing desired control quality in the system.