Abstract: A method of performing a computer implemented analysis of a vehicle in a simulated wading event, the method comprising: defining a trough domain representing a region comprising a water level to be waded by the vehicle; defining a vehicle domain comprising a simulation of the vehicle; the method further comprising: generating a first mesh comprising a plurality of finite mesh elements representing the trough domain; generating a second mesh comprising a plurality of finite mesh elements representing the vehicle domain; defining an overset between the first and second meshes; simulating the wading event by moving the second mesh representing the vehicle domain through the first mesh representing the trough domain, resolving the forces on at least a subset of the finite mesh elements to obtain transient pressures on at least a part of said vehicle domain, and outputting data indicative of said transient pressures