How a Cruise Ship Dry Dock Period Is Planned

A cruise ship dry dock period must fit survey rules. IMO, the flag administration and the classification society set the timing requirements. The work package must fit that window. This guide explains the timing rules and the surveyor’s access needs. It also shows how a superintendent or yard manager can plan around them.

Where the docking date comes from

If the ship holds a Passenger Ship Safety Certificate, the clock is tight. The IMO survey guidelines, resolution A.1207(34), Survey Guidelines under the HSSC, 2025, give that certificate a maximum validity of 12 months. The ship can complete its renewal survey within the three months before expiry without losing any validity.

SOLAS chapter I, regulation 7(b)(ii), requires an inspection of the outside of the ship's bottom at every renewal of that certificate. The guidelines then set how many of those inspections must take place in dry dock:

• at least two of the bottom inspections in any five-year period should be in dry dock, with no more than 36 months between any two dry-dock inspections;
• where the flag administration accepts it, a passenger ship that is not a ro-ro passenger ship can reduce this to one dry-dock inspection in five years, with no more than 60 months between them;
• bottom inspections not done in dry dock can be carried out afloat, inside the same three-month window before the certificate expires.

In these rules, "any five-year period" means the five-year validity of the International Load Line Certificate. Therefore, read the load line and passenger certificate dates together. Missing the date has a hard consequence. If the ship does not complete the survey within the maximum interval, its Passenger Ship Safety Certificate should cease to be valid. This remains the case until the survey is complete.

The classification society adds its own interval

IACS member societies apply Unified Requirement Z3 (UR Z3, Rev.8). It calls for at least two examinations of the outside of the bottom in each five-year special survey period. One must coincide with the special survey. Also, the interval between two examinations must never exceed 36 months. Some societies call the special survey a class renewal survey. Z3 also states that complying with it does not release the owner from SOLAS, especially where SOLAS sets shorter intervals for a ship type.

Z3 allows a three-month extension of the bottom examination only in exceptional circumstances. These include unavailable dry-docking or repair facilities. They also include unavailable essential materials, equipment or spare parts, and delays due to avoiding severe weather. Treat the extension as an emergency margin, not as planning time.

How the flag decides on one docking in five years

Reducing to one docking is a flag decision, and each flag sets its own conditions. One example is the Bahamas Maritime Authority's Marine Notice 75 (version 1.1, October 2024). It sets several conditions for in-water bottom surveys. For example, there must be no overdue conditions of class affecting the bottom. A class-approved diving company must follow an approved survey plan. The site must also have sheltered water with weak currents. These are examples, not the full list of conditions. The company asks its classification society to apply to the flag at least four weeks before the intended survey date. Other flags may apply different rules, so check your own flag's current notice for each ship.

What the surveyor must see during the cruise ship dry dock

The IMO renewal survey guidelines list the bottom items: bottom and bow plating, keel, bilge keels, stem, stern frame, rudder, sea chests and strainers, rudder bearing clearances, the propeller and shaft seals as far as practicable, and propeller shaft clearances. UR Z3 adds detail that shapes the dock layout:

• The ship must sit on blocks of sufficient height, with staging, so the shell plating, stern frame, rudder, sea chests, valves and propeller can be examined.
• The surveyor checks shell plating for excessive corrosion, chafing, grounding damage, unfairness and buckling. The connection between bilge strakes and bilge keels needs special attention.
• The surveyor examines sea chests, gratings, sea connections and overboard discharge valves. Valve opening need not occur more than once per special survey period, unless the surveyor considers it necessary.
• If the surveyor considers it necessary, the team lifts the rudder or removes inspection plates to examine the pintles.
• The surveyor examines side thrusters and other manoeuvring propulsion units externally, including their sealing arrangements.

Each item needs access, staging and a slot in the sequence. If the rudder might have to come off, plan lifting gear, space and people for it before the ship arrives, not on day three.

Building the work package around the survey

The survey items are fixed. The owner's own work list, for example piping renewals, machinery overhauls or accommodation work, has to fit around them. A practical sequence:

1. Confirm the window. Put the passenger certificate expiry, the load line certificate dates and the class special survey date on one timeline and choose a docking that satisfies all three.
2. Notify class early. UR Z3 requires the owner to notify the class society whenever the bottom can be examined in dry dock. Submit an in-water survey proposal in advance so the parties can agree the arrangements.
3. Define each scope. For every job, state the system, drawings, materials, access conditions and who is responsible for testing and acceptance.
4. Plan surveyor attendance. Under the HSSC guidelines, important repairs or renewals require an additional survey. Agree early which jobs will need it.
5. Keep a margin for findings. UR Z3 separates deterioration that needs immediate repair from items that are only recorded. Hold trades and time in reserve for the first kind.

From RAM's projects

RAM's published records include pipe fitting on cruise vessels in dry dock in the Bahamas, across several ships: small-bore pipework, valves and supports installed to the yard's programme and permit system. A separate, anonymized cruise-vessel dry-dock pipework case study documents installed small-bore pipe runs, valves, connections and supports in a constrained technical space. That case study does not disclose the vessel, client, workforce or duration.

The same programme pressure shows at the other end of a build. On Icon of the Seas, RAM's 40-person team carried out mechanical and interior outfitting for 3 months at Meyer Turku, Finland, and continued for 4 weeks in Cádiz, Spain, during the sea-trial phase.

These records share one feature: the work window. RAM's marine page puts it this way: marine projects run against narrow operational windows, such as a docking slot, a delivery date or a sailing schedule, and the question is whether the right trade is on the work front while the window is open. For a dry-dock or repair scope, RAM first asks for system information, drawings and the access window. The team also checks the required trades and acceptance responsibilities. It then reviews the actual scope before mobilisation. Headcount comes out of that conversation; it is not the opening question.

For cruise refits, RAM and the client agree the rooms, systems, materials and finishes for each project. They also define the division of responsibilities. Client and vessel identities remain confidential. Procurement teams can request project-appropriate personnel, qualification and HSE documentation.

Where to start

Start with the certificates, not the yard. Mark the latest legal docking date on one timeline and build the work package backwards from it. Check each requirement against the current text of your flag and class rules, because they can differ by flag and by ship.

To discuss a docking, send the vessel type, location, dry-dock window and required trades to the RAM team, or see how RAM supports cruise ship refit and repair work.