  We consider solutions to the Cauchy problem for an internal-wave model
derived by Camassa-Choi in a paper in Journal of Fluid Mechanics (1996). This
model is a natural generalization of the Benjamin-Ono and Intermediate Long
Wave equations in the case of weak transverse effects. We prove the existence
and long-time dynamics of global solutions from small, smooth, spatially
localized initial data on $\mathbb{R}^2$.
