Remotely operated vehicles equipped with a robotic manipulator are utilized in several underwater/deep sea applications. Control of these type of systems are mostly provided by obtaining the proper position for the end effector of robotic manipulator which constitutes the desired motion for remotely operated vehicle. This situation makes the control of robotic manipulators is really important subject for underwater applications. In this work, we study tracking control of a one degree-of-freedom rigid link in a cross flow. Systems operating at underwater (including this one) are hard to model accurately, and as a result their models include several uncertainties. To reject these modeling uncertainties and external ones, two robust controllers are proposed. Stability of the closed-loop system and the asymptotic convergence of the tracking error are proven mathematically. Numerical simulations are performed to demonstrate the viability of the proposed controller.