A control system based on feedback linearization is developed for a high-speed supercavitating underwater vehicle. The supercavitation bubble surrounding the body leads to reduced drag but is also responsible for the undesired switched, nonlinear and delay dependent behavior caused by the phenomena known as planing. The theoretical contributions of the switched control design are discussed in connection with the mathematical description of the system. Special attention is made to understand and handle the complex and novel dynamics of the vehicle.