The problem of formation control of ship fleet is studied. Under Cartesian coordinates, a model for ship formation
control is established. Based on backstepping technique and Lyapunov direct method, a controller for formation control of
ships fleet is designed by utilizing leader-follower approach. By using the designed control method, the ship fleet can navigate
in the desired formations. Considering heading angle errors between leader and follower ships, the stability of the heading
angle of follower ship is guaranteed to avoid vibrating follower ship under sail. Numerical simulations show the correctness
and effectiveness of the proposed controller.