Glossary Term
Class Approval
Class approval is the formal acceptance by a classification society that a yacht’s design, modification, repair, installation, or test result meets the applicable class rules. In superyacht work, the term usually appears during new build, refit, major equipment replacement, structural repair, machinery changes, or system alterations that affect the classed condition of the vessel. Depending on delegation, some related statutory items may move alongside it, but class approval itself belongs to the class framework.
The approval path depends on the subject. Structural modifications, shafting changes, steering gear work, pressure systems, watertight arrangements, fire-rated divisions, lifting appliances, and significant electrical changes commonly require drawing review before fabrication or installation starts. Some items then move to onboard survey, measurement, pressure testing, alignment checks, insulation resistance tests, or witnessed trials once the work is complete. Approval is therefore both a document exercise and a physical verification exercise.
On refit projects, class approval is tied to the submitted basis of design and to the yacht as actually delivered. Drawings, calculations, material details, equipment data, and revised schematics need to line up with the installed condition. If the yard changes routing, scantlings, foundation details, cable protection, or equipment arrangement during execution, the submission set usually needs to be updated as well. That is one reason a disciplined technical drawing package remains central even when experienced trades and OEM technicians are involved.
When class approval is late, unclear, or treated as an afterthought, procurement and installation can move ahead of the accepted design. The result is often rework, delayed certificates, or operational restrictions at handover. Owners, managers, captains, and chief engineers benefit from asking a direct question early in the job: does this item require class approval, flag acceptance, both, or neither?