Overview
ISO 11347:2024 - Ships and marine technology - Large yachts - Measurement and assessment of the visual appearance of coatings - defines technical requirements and practical measurement procedures for evaluating the above‑waterline superficial coatings of large yachts (length of hull LH ≥ 24 m as per ISO 8666). This second edition updates terms, normative references and the test/recording methods used to assess the final finish before acceptance.
Key topics and technical requirements
- Scope & intent: Applies to large yachts used for sport, leisure or commercial operations; focuses on appearance inspection and acceptance of the final top coat above the waterline.
- Measurement vs visual assessment: Combines objective instrument measurements and standardized visual observations (normal or corrected vision, 500–1 000 lx or daylight, viewing distance >75 cm, incident angle ≥30°).
- Measurable effects (instrument-based):
- Fairness - large‑scale surface smoothness; measured with a linear bar and feeler gauge (Annex A).
- Distinction of image (DOI) - clarity of reflected image; measured by optoelectronic devices (wave‑scan, goniophotometer) (Annex B).
- Orange peel - texture similar to citrus skin (0.1–30 mm wavelengths); measured optoelectronically (Annex C).
- Microstructure - sub‑0.1 mm features affecting visual perception; measured with wave‑scan or goniophotometer (Annex D).
- Colour - spectral measurement using spectrophotometers (Annex E).
- Gloss - measured according to ISO 2813 and Annex F.
- Particulate contamination - measurement methods in Annex G.
- Visually assessed effects (classified into three groups):
- Group 1 - point defects (cratering, fisheyes, pinholes, dimples)
- Group 2 - localized defects (sags, brush marks, sanding marks, tape/cut lines, blisters per ISO 4628‑2, cracking per ISO 4628‑4, etc.)
- Group 3 - generalized defects (blushing, blooming, print‑through, overspray, cissing, striping/clouding)
- Documentation: Normative annexes A–G specify test methods; Annexes H–J define recording methods for the three visual groups.
Applications and users
- Who uses it: yacht builders, shipyards, paint and coatings manufacturers, quality control inspectors, marine surveyors, naval architects, owners and purchasing agents.
- Practical uses: acceptance inspections, contract compliance, quality assurance in painting and finishing, benchmarking coating performance, refurbishments and repairs, supplier and warranty disputes resolution.
Related standards
Keywords: ISO 11347:2024, large yachts, coatings, visual appearance, fairness, DOI, orange peel, microstructure, colour measurement, gloss, particulate contamination, yacht inspection, marine coating standards.