We present a virtual software simulation system for remotely-operated vehicle (ROV) operations in arctic and harsh environments particularly focused on subsea trenching. The system provides interactive, three-dimensional graphics and dynamics simulation with high fidelity. In addition to standard ROVs, the system can now simulate trenching and dredging vehicles such as jetters and ploughs. It also provides support for integration of data for visualization and analysis from a wide range of sources including sub-bottom imaging, seismic, bathymetry and sidescan sonar. Visualizations can be controlled to enhance features important for geological and geotechnical analysis.