The classification of commercial ships is usually classified according to their uses. The current internal structures are as follows:

1. Passenger ship refers to the ship used to transport passengers and their luggage. A passenger ship carrying a small amount of cargo is also called a passenger and cargo ship. Since most of the passenger ships follow the scheduled route, they are also called passenger ships. It has good navigation performance, perfect safety equipment and living facilities, high superstructure and high ship speed, which is usually about 20KN (knots, nautical miles per hour). Some short distance passenger ships use hydrofoil and hovercraft, and the speed is generally about 40 kn.

2. According to the different structure and equipment of cargo ship, dry cargo ship can be divided into ordinary cargo ship and bulk carrier.

3. For ore carrier, due to the large proportion of ore and small space occupied, the center of gravity of the ship is low. Therefore, in order to increase the height of the center of gravity, the double bottom is very high, and the ballast tanks on both sides of the cargo hold are also large.

4. Container ship refers to the ship mainly carrying container cargo. The goods are loaded into containers in advance, and then the containers are loaded onto the ship. The advantages of this mode of transportation are high loading and unloading efficiency, reducing labor intensity, reducing cargo damage and bad goods, and promoting multimodal transport.

5. Ro ro ship is also called ro ro ship. When the ship loads and unloads goods at the wharf, the springboard is first put on the shore from the stern of the ship, and then the container is towed into the cargo hold through the trailer. As a result, it has a special structure, with a flat upper deck, no pulleys and arches, no cargo equipment, a large number of decks (2-4 floors), few struts in the cargo hold and a longitudinal deck. High cost. The velocity is 16-18kn. The goods it carries are mainly cars and containers. The advantage of this kind of ship is that it does not rely on the loading and unloading equipment on the wharf, and the loading and unloading speed is fast, which can accelerate the turnover of the ship.

6. A timber boat is a ship specially used for loading timber or logs. The hatch of this kind of ship is very large, and there is no beam or other equipment to hinder loading and unloading. Wood can be loaded on the engine room and deck. In order to prevent the wood on the deck from being washed away by the waves, bulwarks of not less than one meter are usually installed on both sides of the ship's side. The cargo hold shall be long and large, and there shall be no props in the cargo hold.