Building to class means designing the boat to a classification society's rules and building it under the supervision of its surveyors. The boat is delivered with a class certificate, maintained through periodic surveys.
The process
- Plan approval. Structural, machinery and systems drawings are submitted to the society and approved.
- Materials. Class-approved or certified materials; certificates checked at acceptance.
- Production supervision. The class surveyor attends at set stages: welding, lamination, tests.
- Tests. Tightness, systems tests and sea trial.
- Certificate. Once every stage is complete, the class certificate is issued.
Why choose it?
- A structure documented against an independent society's rules.
- May be required for commercial use or under certain flags.
- Documentary value for insurance and resale.
Points to watch
- Plan approval and supervision add time and cost; build them into the schedule from the start.
- Class is kept through periodic surveys; a missed survey can suspend class.
- Class supervision does not replace the owner's own independent supervision: class checks conformity with the rules, the owner's supervisor checks conformity with the specification and contract.
What a classification society does
A classification society is an independent technical body that certifies a boat has been designed and built to its rules. Before the build it approves drawings and calculations; during the build its surveyors attend the yard at set stages; it applies its own requirements on matters such as materials and welding. On completion a class certificate is issued, and the boat undergoes periodic surveys to keep its class.
Advantages
- Independent oversight throughout the build.
- A documented structural history at resale.
- Preferred by some insurers and lenders.
- A sound basis for documents that commercial use may require.
Cost and time
Building to class adds cost and time through class fees, approval processes and some material and document requirements. Keeping class also needs regular surveys and maintenance. So the decision follows the boat's intended use, size and the owner's resale plans.
Relation to the owner's inspector
The class surveyor checks that the rules are applied; following the owner's interests and the quality expectations in the specification is the owner's inspector's job. Class rules set a minimum; the specification's materials, workmanship and finish may be above it. The two inspections complement each other.
Societies
Several international classification societies work in yacht building, and Turkey has a national one too; the choice depends on where the boat will be used and the owner's preferences.
Documents
Class approval letters, survey reports and the certificate go into the build file; they are what a future buyer or insurer will ask to see.
Keeping class
A class certificate stays valid only if the boat passes periodic surveys: annual, intermediate and, at set intervals, a thorough renewal survey. Findings from these surveys must be put right within a set time, or class can be suspended. When buying a classed boat, whether class is current and any findings open are confirmed with the society.
The owner's decision
A mid-size boat for private use is often built without class, through the CE route with independent supervision. If commercial use, large size or markets where buyers expect class are in view, building to class may be the better choice. The decision is made before the build starts; moving into class part-way is often hard or impossible, as earlier stages would need to be documented.
So the question of class is settled between owner and designer at the design stage.