Ship repair refers to the repair of the part of the ship damaged by an accident. If the scope of this type of repair is not large, it can generally be carried out along with the voyage repair project. However, if the scope of the project is large and the voyage repair is difficult to perform, a repair plan must still be arranged. The items, scope and time limit of accident repair shall be determined in accordance with the actual damage and repair requirements contained in the ship inspection report of the ship inspection agency. Accident repairs are still required to be issued to the repairing shipyard before repairs are carried out. For minor accidental damage, provided that the airworthiness performance is not affected, and safe operation is not hindered, a record can be made, and it can be repaired when the maintenance and repair are planned. For accident repair items, the ship repair list should be compiled together with "accident repair", and the shipyard is required to issue an invoice for this part of the repair cost, and stamp the word "accident repair" on the invoice as a proof of claim.

Ships that have been out of service need to be repaired to restore seaworthiness and hull strength, such as repairs to the wreck of sunken ships and fire ships. This type of repair project is huge, requires huge amounts of money, has a long ship repair period, and has poor economic results. It is now rare.

According to the complexity of ship repair, it can generally be divided into dock repair, annual repair, and overhaul.

(1) Dock repair: ship repair projects are relatively large, and the quality inspection requirements are high (generally according to the national annual inspection regulations). Docking repairs such as painting, deck machinery, engine room machinery, tail shafts, and propellers are required. , The hull of the ship and the outer shell of the superstructure must be overhauled.

(2) Annual repairs: ship repair projects are relatively small and rare compared to major repairs, but still need to be cleaned and painted, deck machinery, engine room machinery, ship hulls, stern shafts, propellers and other partial repairs.

(3) Maintenance: In addition to painting below the waterline, this type of ship repair generally does not require docking repairs, and only overhauls and overhauls are carried out at the ship-repairing pier, mainly for mechanical equipment repairs.