APC vs Significant Modifications

The difference between “APC” and “Significant modifications to non-CE marked pleasure craft”.

Why is it necessary to understand the difference between “APC” and “Significant modifications to non-CE marked pleasure craft”?

Owners who decide to make significant modifications to their vessel need to be aware that the vessel will need to undergo checks to verify compliance with technical safety requirements.

Depending on the year of construction of the vessel, a different procedure will be implemented: Post-construction assessment (APC) or a safety inspection to assess suitability for navigation.

To determine the correct procedure, it is important to know whether the vessel was built before or after 1998 and whether it is CE marked or not. APC is conducted in the case of modifications to CE marked vessels, while the safety inspection for “Significant modifications” pertains to non-CE marked pleasure craft.


Significant modifications are substantial transformations that significantly alter the configuration of the vessel, compromising compliance with the technical requirements outlined in the Declaration of Conformity.

Among the significant modifications is, for example, the replacement of the main propulsion engine. In such a situation, it may involve installing one with different “installed” power or greater weight, or even varying the number of installed engines.

Other modifications may include:

  • Changing the main dimensions: increasing/reducing the length or width of the pleasure craft;
  • Increasing/reducing the number of people that can be carried;
  • Increasing/decreasing the maximum load capacity;
  • Altering the propulsion/transmission system;
  • Modifying the fuel system;
  • Changing the distribution of weights on board, which may affect the stability and buoyancy requirements of the vessel;
  • Extending the navigation limits;
  • Other significant modifications affecting safety requirements.


In addition to the relevant modifications listed, in the case of a CE-marked vessel, situations may arise that require the implementation of a Post-Construction Assessment (PCA).

Private importers often purchase vessels from non-European manufacturers. In this scenario, since the design and production phases occur outside of the European territory, to import the vessel regularly, it is necessary to verify safety requirements through a post-construction assessment before commissioning.

Another scenario occurs when the owner changes the intended use of the vessel, for example, converting a vessel previously used for fishing into a pleasure craft.

If an owner constructs a pleasure craft for personal use, they must wait 5 years before being able to sell it. If they decide to sell it before this period is over, they must subject the vessel to a post-construction assessment.

A PCA is also required when an importer makes modifications to a vessel already built that impact compliance with the requirements set by the directive. Additionally, introducing a pleasure craft to the market under one’s own name or brand also requires a PCA, as the importer is then considered the manufacturer.

Relevant Modifications to Non-CE Marked Pleasure Craft

If any of the aforementioned modifications are made to units built before 1998 or not CE-marked (e.g., vessels used for regattas), it is still necessary to carry out technical assessments to verify compliance with safety requirements.

In this case, the reference regulation is “Circular MIT PROT. 0014281 of 21/05/2019,” which establishes that any modification to the unit that affects the essential safety requirements established by Legislative Decree 171/2005 requires verification of these requirements.

In this scenario, to regularize the unit, the boat owner can turn to ENAVE to obtain the certificate to be presented to the Maritime Authority.

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