ISO 8666:2020

Overview

ISO 8666:2020 - "Small craft - Principal data" defines standardized terms, measurements, masses and loading conditions for small craft with a hull length (LH) up to 24 m. The standard provides a common vocabulary and measurement methodology so manufacturers, designers and authorities can publish and interpret principal data (dimensions, displacements and mass figures) consistently across products and documents.

Key topics and technical requirements

ISO 8666:2020 covers:

• Definitions and terms: clear definitions for waterline, maximum load waterline (reference waterline), sheerline, transom beam, displacement, loaded displacement, displacement volume, design trim, reference sail area, etc.
• Symbols, designations and units: standardized symbols and SI units for all principal data to avoid ambiguity.
• Measurements:
  • Longitudinal: maximum length, length of hull, waterline length.
  • Athwartship: maximum beam, beam of hull, transom beam, waterline beam.
  • Vertical: maximum depth, midship depth, freeboard, draught.
  • Other geometric data: deadrise angle, windage and sail areas, hull volume.
• Mass specifications:
  • Net and gross shipping mass, light craft mass, performance test mass, trailer towing mass, maximum load.
  • Clarifies what equipment and fittings are included or excluded for each mass definition.
• Loading conditions: standardized loading states such as test condition, ready-for-use, fully loaded ready-for-use, empty, light craft, minimum operating and maximum load conditions.
• Tolerances and publication rules: guidance on tolerances for published data and preliminary specifications.

Practical applications and who uses ISO 8666:2020

ISO 8666 is practical for anyone needing reliable, comparable principal data for small craft:

• Boat designers and naval architects - to document and communicate hull dimensions, displacements and trim consistently.
• Boatbuilders and manufacturers - to produce specification sheets, user manuals and conformity documentation.
• Marine surveyors and certifying authorities - to verify declared dimensions and masses and assess compliance.
• Dealers, buyers and insurers - for accurate performance estimates, registration, towing requirements and insurance quoting.
• Regulatory bodies and testing labs - to set test conditions and interpret displacement and loading data reproducibly.

Related standards

ISO 8666:2020 is part of ISO/TC 188 work on small craft. For complete safety, structural and stability requirements, consult other small-craft standards and regional regulations that address stability, structural design and onboard safety equipment.

Keywords: ISO 8666:2020, small craft principal data, small craft dimensions, loaded displacement, mass specifications, loading conditions, boat design, marine survey.