“…For nonlinear wave modelling, these models are computationally much faster than the Navier-Stokes equations and well-explored in the wavemodelling applied-mathematics community. For numerical wave modelling, e.g., we refer to boundary/finite-element models of Ma et al [19], Engsig-Karup, Bingham [11] and Boussinesq models [18], the latter which use optimised and reduced vertical resolution (for other variational models see [14], [15], [10]). Typically, second or higher-order time discretisations are used such as compatible modified midpoint ( [8], [10]) or Runge-Kutta schemes.…”