Underwater vehicle technology has been gaining in importance in the last few years. Large sections of the earths oceans remain unexplored. The quest for energy resources under the water has given an impetus to develop fast moving underwater vehicles capable of traveling along a complex 3D trajectory. This book describes the development of a small autonomous underwater vehicle or AUV known as the Hydrocopter that can mimic the motion of a helicopter. A model was constructed and tested in a deep water tank at Memorial University of Newfoundland, Canada. Normally the development of a new idea...