The purpose of this work was to investigate the application of pump jet propulsion and yaw angle stabilization for a landing craft going through the surf. Linear theory was used throughout the analysis of the control problem. The stability indices and derivatives were determined in part by experiment and the remainder by analytic techniques. It was found that LCVP landing craft are dynamically unstable without a skeg. Stability could possibly be restored by a feedback control system, but the far more practical solution is to start with a dynamically stable craft. This will provide the craft with a greater margin of stability in all cases. Although it is felt that the craft can not be satisfactorily used without a skeg, much of the analytic data in Appendix A may be used to cover the case with a skeg. Reference (3) contains the appropriate modifications needed for the changes.

http://archive.org/details/yawstabilization109459675