Under normal circumstances, there is reliance first, and the stern depends on peace first. Ordinary medium and small boats usually rely on headwind and top current first, and generally do not need the assistance of tugboats. Ships can berth by their own anchors and cars. Generally, large ships are assisted by front and rear tugboats and berthed in parallel. The large ship is huge, so it is difficult to dock by its own equipment, and it must be assisted by tugboats. Ro-ro passenger and cargo ships are generally used for stern berthing. This kind of boat is generally a two-wheeled vehicle with head-to-side push, and its operation is more flexible. In addition, these ships have car loading and unloading bridge plates, and most of the previous ships were installed at the stern, so this berthing method was adopted for the convenience of loading and unloading. But now the ro-ro ship has bridge plates at both ends.