Abstract: We discuss model equations for the description of horizontally propagating waves in the interior of a density stratified ocean in a rotating reference frame (e.g a rotating planet). Using linear theory we outline the complications the inclusion of rotation introduces. These complications preclude the strict application of equations in the classical Korteweg-de Vries (KdV) hierarchy. In place of the well-studied KdV-type equations, the so-called Ostrovsky equation is often employed to describe waves in the presence of rotation. However, this equation lacks the mathematical structure of the KdV equation, and in particular is not fully integrable. We present numerical integrations, based on spectral methods, of the Ostrovsky equation which show that solitary wave-like solutions decay slowly by radiating energy to a tail of dispersive waves. We discuss the shortcomings of the Ostrovsky equation and propose an alternative model equation that captures the linear, dispersive wave behaviour exactly.