In the case of preparing the ship for the shipyard, as a first subdivision, we can separate them into two types.

• The Vessel must be lifted onto the dock.
  As we know, the Class Company requires two dock climbs for inspections to be carried out throughout the five-year period.
  • The intermediate Survey at two and a half years. To which the Class Companies authorize the companies that an Underwater Survey can be carried out as it is called (UWS Underwater Survey) for this intermediary Survey. Class companies authorize this if the vessel meets specific requirements to carry out the same. It is the only Survey that can be carried out afloat with the help of divers certified by the Class.
  • The five-year Survey during which the ship must be docked and carry out different types of maintenance such as measuring the thickness of the hull plates, verification of clearances in the rudder and propeller shaft, and maintenance on stabilizer systems, if necessary. Paint on the Hull, draft marks, antifouling coating, etc.
  • In the last case, if the ship must go up to the dock for any preventive or emergency repair, that affects the structure and puts its buoyancy reserve at risk. This type of maintenance shipyard is usually called an unscheduled or emergency shipyard.
• The Vessel may undergo repairs but be afloat.
  This can be done when the repairs do not require the vessel to be docked. These repairs do not affect the vessel’s structure to the point that its stability or buoyancy reserve is compromised.
  Generally, they are repairs in the engine room or its structure, such as inside cargo holds, ballast, fuel or cargo tanks, passenger or crew cabins, or any maintenance above the water line. Flotation of this does not affect its buoyancy reserve, as we have discussed.
  
  

  Before all these points that companies consider regarding the shipyard period of a ship, companies consider these extremely important details.

  • The Type of Vessel: Not all shipyards worldwide have the necessary facilities to meet the demands of ships or companies regarding the type of ship. EX. In the Mega Yacht industry, shipyards have different facilities than the facilities of a commercial or cargo shipyard. Garages or structures protect the ships to obtain an atmosphere controlled by the complex painting processes of these ships. Apart from that, in a commercial or merchant shipyard, the air is sometimes contaminated with sand particles due to the cleaning of the hulls of other vessels, causing severe damage to the paint and decks of the Mega Yachts.
  • Size of the vessel: For large vessels such as Bulk Carrier, Super Tanker, Cruise Ships, and Container Ships, companies look for shipyard facilities that adapt to the convenience of the vessel. In some cases, companies have agreements with shipyards to carry out different types of maintenance on ships in the fleet. In other cases, they are chosen by the route that the ship is operating and by the price of the work to be carried out.
  • Types of shipyards: According to the size of the ship, tonnage, and work that must be carried out, the type of shipyard used. The most common types of shipyards are:
    
    • Dry docks (Graving Docks)
    • Floating Docks
    • Mechanical lift docks with transfer systems
    • Sliding carriage handrail. (Slipways)