What is a boat's CE design category? A, B, C and D explained

UPDATED 10 NOVEMBER 2026 · 2 SOURCES

Every CE-marked boat carries a design category, A to D. What each means in wind and waves, how load changes it, and what a surveyor checks on the builder's plate.

DEFINITION

Design category

The A, B, C or D rating on a CE boat's builder's plate, stating the wind and wave conditions it was designed for.

ALSO CALLED: CE DESIGN CATEGORY, RCD CATEGORY A B C D, CATEGORY A OCEAN

Every CE-marked boat from 2.5 to 24 m carries a design category on its builder's plate. It says the conditions the boat was designed for, assessed under ISO 12217.

Category	Name	Wind	Significant wave height
A	Ocean	Above force 8	Above 4 m
B	Offshore	Up to force 8	Up to 4 m
C	Inshore	Up to force 6	Up to 2 m
D	Sheltered waters	Up to force 4	Up to 0.3 m

Why it matters in Europe

National rules tie equipment and areas to it. Spain's Real Decreto 339/2021 limits a CE boat's navigation zone by its category, and Croatia maps categories to its navigation areas.

What a surveyor checks

The plate: category, maximum persons and load, and that the owner's manual agrees. Then the intended use, and any changes that add weight high up.

Frequently asked

What does design category B mean?

Offshore: designed for winds up to force 8 and significant wave heights up to 4 m, from Sailboat Cruising and YachtBuyer.

Is the design category about distance from shore?

YachtBuyer stresses it's about wind force and wave height, and that it depends on load: its example yacht is category B with 12 aboard and C with 14.

Standards it's judged against

ISO 12217

Small craft, Stability and buoyancy assessment and categorization

What the RCD design categories A, B, C and D mean in wind force and wave height, how ISO 12217 stability assessment sets them, why load changes the category, and how surveyors use them in a report.

What surveyors check

RCD 2013/53/EU

Directive 2013/53/EU on recreational craft and personal watercraft

What the EU Recreational Craft Directive covers, which boats it applies to and which it excludes, the CE marking and builder's plate, private imports and post-construction assessment, and what a surveyor checks on a CE-marked boat.

What surveyors check