Remotely Operated Vehicles (ROVs) are of great importance for a wide range of underwater missions. Although being controlled by a human operator, there is yet the desire to enable some basic autonomous behavior to relieve the operator from controlling every single movement. An accurate model is the basis for any reasonable controller design, not only to find suitable controller parameters, but also to test and optimize controllers in simulation before using them at the vehicle in reality. This paper discusses the procedures of modelling, parameter identification and the design of essential control algorithms for an existing ROV. The model considers kinematics, kinetics and thruster allocation. Two used procedures for parameter identification are presented; a third one as well was recently published in another paper. Finally, we discuss the controller design and show the simulative validation for set-point regulation and waypoint tracking.