The three-dimensional gait of a snake-like robot moving in water was studied according to underwater environment characteristics. A model for underwater snake-like robots with vertical and horizontal joints was established based on the dynamic simulation software called the virtual robot experimental platform(V-REP). Based on the serpenoid curve,the model's depth in water was changed step by step to realize the rising and diving motions. The position,exerted force,joint torque and motion efficiency of snake...