Individual Based Models (IBMs) provide a way of taking simple rules and principles and simulating the movement and interaction of living creatures with each other and/or the environment around them. These models have been used to investigate habitat use and movements of a variety of animals, including both marine and terrestrial mammals, fish and birds, over a range of timescales and degrees of sophistication. An advantage of this type of model is the potential to allow changes to the environment to be simulated, and potential effects of these changes to be investigated before they take place. This could include potential impacts of marine energy devices on local marine mammals. This model uses meshes and tidal flow data from an openTELEMAC model, with the 3D mesh being composed of linear, wedge shaped elements with nodes fixed in x, y but with time varying z coordinates. Data values (such as x, y and z flow velocities, prey density or noise levels) are specified at each node and are interpolated spatially using mean value coordinates and interpolated linearly with respect to time in order to obtain values at the location of each individual animal, or boid, within the simulation. The movement of the mesh, including the changing heights of the elements, leads to a variety of issues when tracking the location of the boids within the mesh.