Operational Guide · Registers & Logbooks

# Survey in Dry Dock

The moment when Class, flag and shipyard converge on the same ship: how to organize mandatory surveys without letting them become the bottleneck of the entire stoppage.

special survey special survey renewal survey class

## Operational Explanation

The dry dock period is often the only opportunity, under the five-year Class cycle, to conduct surveys requiring direct access to parts of the ship not inspectable while afloat: the hull bottom, rudder, propellers, sea chests, sea cooling systems. The Special Survey (Special Survey/Renewal Survey), conducted every 5 years, is typically the most extensive and requires the greatest documentary and technical preparation.

An organizational particularity often underestimated: multiple parties (Class surveyor, flag inspector if required, shipyard personnel) must coordinate on the same ship during the same period, with direct consequences on timing if planning does not anticipate this coordination need.

## Regulatory Reference

Requirements of the applicable Classification Society for the five-year survey cycle (Annual, Intermediate, Special/Renewal Survey), in implementation of the statutory SOLAS/MARPOL requirements for the related certification; the Renewal Survey renews the Class Certificate and the associated statutory certificates.

## Scope of Application

Every classed ship, according to its own five-year survey cycle; the Special/Renewal Survey is generally conducted in conjunction with a scheduled dry dock entry.

## Procedure / How to Complete It

1. Verify in advance the full scope of the Special/Renewal Survey required by the Classification Society for the specific ship.
2. Coordinate the simultaneous presence of the Class surveyor, any flag inspector, and shipyard technical personnel.
3. Prepare the required documentation (approved plans, maintenance history, previous survey reports) before dry dock entry.
4. Carry out the required tests and inspections (thickness measurement, anchor/chain testing, sea chest inspection, rudder testing) according to the sequence agreed with the shipyard.
5. Formally close every class condition raised during the survey, before leaving dock if required.

## Practical Example

Example of coordination: five-year special survey planned with 3 days of overlap between the Class surveyor and the flag inspector, to jointly conduct the inspection of sea chests and sea valves, reducing total downtime compared to separate visits on different dates.

## Real Cases

Prolongations of docking time have frequently been attributed to insufficient coordination between the different parties who must verify the ship (Class, flag, shipyard), with resulting waiting times between one inspection and another adding up instead of overlapping.

## Common Mistakes Mistake Library

Mistake | Consequence | How to avoid it
--- | --- | ---
Presence of Class surveyor and flag inspector not coordinated, with visits on separate dates | Additional waiting time that prolongs the docking period | Coordinate visits to overlap when possible, sharing access to the same inspected areas
Historical maintenance documentation not ready on the surveyor's arrival | Delay in the actual start of the survey | Prepare all required documentation before dry dock entry
Class condition raised during the survey not closed before leaving dock | Need for a subsequent intervention, often more costly and complex while afloat | Plan the closure of every class condition found before the end of the dock period

## PSC Observations

PSCOs verify the validity of the Class Certificate and associated statutory certificates, updated after the Special/Renewal Survey; any class conditions raised and not closed within the required timeframe can affect the PSC assessment.

## Operational Tips

- Coordinate the presence of Class and flag to overlap when possible, to reduce overall time.
- Prepare all historical maintenance documentation before the surveyor's arrival, not during the visit.
- Close every open class condition before the end of the dock period, when technically possible.

## Checklist

- Full scope of the Special/Renewal Survey verified in advance
- Presence of Class/flag/shipyard coordinated
- Historical documentation prepared before dry dock entry
- Required tests and inspections carried out according to the agreed sequence
- Open class conditions closed before leaving dock

## FAQ

How often should the Special/Renewal Survey be conducted?
Typically every 5 years, under the five-year Class cycle, generally in conjunction with a scheduled dry dock entry.
What happens if a class condition is not closed by the end of the dock period?
It is recorded as an outstanding class condition with a deadline for closure; depending on severity, it can affect the validity of the certificate if not resolved within the required timeframe.
Is a flag survey always necessary in addition to the Class one?
It depends on the type of certificate: many flag Administrations delegate their statutory survey authority to the Classification Society (as a recognized organization), but some reserve additional direct verifications, especially for specific certificates or in the case of spot-check inspections.
🎬 Additional photos, videos and interactive diagrams for this topic will be available in a future version of the platform.

## Related Topics

Dry Dock Entry Planning Thickness Measurement (UTM)

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