Who decides a yacht’s CE/RCD design category? And what category are most 65–78 ft cruising catamarans?

For recreational yachts under 24 m, the familiar Category A / B / C / D system usually comes from the EU Recreational Craft Directive (RCD). The category is normally chosen and declared by the manufacturer/designer, supported by stability, buoyancy, structural, and construction evidence. For popular 65–78 ft cruising catamarans, the market overwhelmingly targets Category A.

Contents

1. What the A–D categories mean

The categories are design categories, not a guarantee of safety, crew competence, equipment, maintenance, or actual operating permission. They describe the sea and wind conditions the vessel is intended to be designed and assessed against.

Category Common name Typical design basis Practical interpretation
A Ocean Winds greater than Beaufort Force 8 and significant wave height greater than about 4 m Extended offshore/ocean voyages; largely self-sufficient; designed for severe conditions, though not literally “unlimited.”
B Offshore Winds up to Force 8 and significant wave height up to about 4 m Offshore/coastal passages, including substantial conditions, but not intended for the most severe ocean voyages.
C Inshore Winds up to Force 6 and significant wave height up to about 2 m Bays, estuaries, coastal waters, lakes and rivers where larger seas are not expected.
D Sheltered Winds up to Force 4 and significant wave height up to about 0.3 m, with occasional 0.5 m waves Very protected waters: harbours, canals, sheltered lakes, very calm coastal areas.

Note: “significant wave height” is a statistical measure, not the absolute maximum wave that may be encountered. Also, the category does not automatically define legal operating limits; flag state, charter rules, insurance, crew qualifications, and equipment requirements may impose additional restrictions.

2. Who decides the category, and how?

Short answer

In the EU/EEA recreational craft system, the manufacturer — or the importer/authorised representative placing the boat on the EU market — is legally responsible for declaring the design category. The designer and builder choose the target category and must prove that the boat meets the relevant requirements. They cannot simply label a boat “Category A” without supporting engineering evidence.

The main parties involved

Party Role
Designer / naval architect Selects the target design category with the builder, then performs or supervises the stability, buoyancy, structural, and systems engineering needed to meet that category.
Manufacturer / builder / brand Declares the category, issues the Declaration of Conformity, affixes the builder’s plate/CE marking where applicable, and provides the owner’s manual and technical documentation.
Notified body May be involved in the conformity-assessment process, particularly for higher categories or where harmonised standards are not fully applied. The exact role depends on the applicable conformity route and national implementation.
Classification society Optional or required for some commercial/classed yachts. Societies such as Lloyd’s Register, Bureau Veritas, DNV, RINA, ABS, etc., can apply their own rules and issue class certificates, which are separate from CE/RCD categories.
Flag state / maritime authority For commercial, charter, or passenger-carrying vessels, the flag state may define operating areas, safety equipment, manning, survey, and certification requirements that override or supplement recreational design categories.
Insurance company / surveyor May impose practical operating limits, require a survey, or ask for evidence of category/class before insuring a yacht for offshore or ocean use.

How the category is technically determined

  1. Define the intended service: ocean cruising, offshore coastal cruising, inshore charter, protected waters, commercial passenger use, etc.
  2. Select a target category: usually driven by market expectations, regulatory requirements, and the builder’s positioning.
  3. Perform stability and buoyancy calculations: for catamarans this is especially important. The design may be assessed against standards such as ISO 12217, with multihull-specific criteria including wind heeling, gust stability, reserve buoyancy, downflooding points, flooding cases, and capsize susceptibility.
  4. Assess structural loads and scantlings: hull panels, bulkheads, bridge deck, deckhouse, windows, hatches, rig, appendages, and equipment loads may be assessed using standards such as ISO 12215, ISO 12216, classification society rules, or equivalent engineering.
  5. Prepare the technical file: drawings, calculations, material specifications, construction details, stability booklet/manual, and owner’s documentation.
  6. Declare conformity: if the design meets the requirements, the manufacturer declares the category and issues the relevant documentation. If it does not, the boat must be modified or assigned a lower category/operational limitation.
Important: A design category is assigned to a specific design/hull configuration and loading condition. Major modifications, excessive loading, changes in equipment, or poor maintenance can affect stability, buoyancy, and structural strength. A Category A plate does not mean the boat is safe in all conditions if it is overloaded, improperly configured, badly maintained, or poorly operated.

3. Estimated category split for typical 65–78 ft cruising catamarans

The following is a qualitative market estimate, not an official statistical survey. It assumes typical/popular cruising catamarans in the 65–78 ft range that are intended for private cruising, owner-operated long-distance use, or high-end charter, and that are formally categorized under CE/RCD or an equivalent regime. Some custom or non-EU-market boats may have no formal CE category at all.

Category Best estimate Reasonable range Why
A – Ocean 90% 85–95% Most 65–78 ft cruising catamarans are marketed for offshore and ocean cruising. Buyers expect transoceanic capability, and builders usually target Category A to maximise resale, charter suitability, insurance acceptance, and global marketability.
B – Offshore 8% 4–12% A minority may be coastal-focused, luxury-focused, or intentionally restricted. Some one-off, older, or specially configured boats may also fall here if stability/scantlings or intended service do not support full Category A.
C – Inshore 2% 0–3% Rare in this size range for true cruising catamarans. Possible for protected-water charter, river/estuary-specific designs, or unusual configurations not intended for offshore work.
D – Sheltered 0% 0–1% Essentially none among typical cruising catamarans of this size. A 65–78 ft catamaran designed only for sheltered waters would be highly unusual unless it is really a special houseboat/protected-water platform rather than a cruising yacht.

Visual summary

Category A – Ocean ~90%
~90%
Category B – Offshore ~8%
8%
Category C – Inshore ~2%
2%
Category D – Sheltered ~0%
0%

The bar for Category D is shown at a minimal width for visibility; the practical estimate is essentially zero for normal 65–78 ft cruising catamarans.

How to read this estimate

4. Other classifications and rules you may see

CE/RCD Categories A–D are the most familiar recreational categories in Europe, but they are not the only system. Depending on the vessel, flag, and use, other frameworks may apply.

System / framework Typical use Who controls it Notes
EU/EEA Recreational Craft Directive (RCD) Categories A–D Recreational craft, generally 2.5–24 m hull length Manufacturer/designer; notified body may be involved This is the source of the familiar CE Category A/B/C/D system. It applies when the craft is placed on the EU/EEA market, subject to certain exclusions and measurement rules.
ISO standards Engineering basis for CE/RCD compliance Designer/builder, sometimes reviewed by notified body Commonly used standards include ISO 12217 for stability and buoyancy, ISO 12215 for hull construction/scantlings, ISO 12216 for windows/hatches, and ISO 8666 for measurement definitions.
Classification societies Commercial yachts, large custom yachts, charter yachts, owner-requested class Lloyd’s Register, Bureau Veritas, DNV, RINA, ABS, etc. Class rules may cover hull, machinery, safety, and service restrictions. Class is different from CE category and may use terms such as unrestricted, offshore, coastal, or restricted service.
Flag-state commercial codes Charter, passenger-carrying, or commercial vessels National maritime authorities Examples include UK/MCA small commercial vessel rules, US Coast Guard passenger vessel rules, Australian NSCV, and other national codes. These may define operating areas, passenger limits, crew, safety equipment, and survey intervals.
ABYC and NMMA standards Common in the United States Builder/manufacturer; certification may be voluntary or market-driven ABYC standards cover many safety and construction topics. They are not identical to CE categories and do not automatically map to A/B/C/D.
Insurance or survey restrictions Practical operation of private yachts Insurer, marine surveyor, owner An insurer may limit a boat to coastal waters, impose weather windows, require additional equipment, or request evidence of category/class before covering offshore passages.
Marketing terms Sales brochures and websites Builder/marketing department Terms like “bluewater,” “offshore,” “ocean-ready,” or “explorer” are not regulated by themselves. They should be supported by CE category, class, or engineering documentation.
Length matters: The CE/RCD system generally uses a measured hull length. A boat advertised as “78 ft” may be close to the 24 m threshold, and details such as bowsprits, swim platforms, load-line length, hull length, and flag-state definitions can affect which rules apply. For a specific yacht, the exact measurement and regulatory status should be checked.

5. What do most designers of 65–78 ft cruising catamarans design for?

Most designers of popular 65–78 ft cruising catamarans aim for CE Category A or an equivalent offshore/ocean capability, because that is what the market expects at that size and price point. Even if the average owner spends most of the time in coastal waters, the boat is usually engineered to support the idea of ocean passages, long-distance cruising, and high resale value.

Category A as the default target

Buyers of large cruising catamarans often expect bluewater capability. Builders therefore usually target Category A to avoid limiting the boat’s market, charter appeal, insurance acceptance, or perceived value.

Comfort is often prioritised

Designers usually optimise for spaciousness, stability at anchor, ease of handling, shallow draft, and comfortable coastal/offshore cruising. Category A compliance provides a safety/design margin, but it does not mean the boat is intended to seek out storms.

Catamaran-specific challenges

Multihulls rely heavily on beam, buoyancy, and intact stability. Designers must pay special attention to windage, righting moment, bridge deck loads, watertight integrity, escape routes, reserve buoyancy, and stability after flooding or damage.

Weight and payload matter

A catamaran’s category can be sensitive to weight. Extra equipment, watermakers, generators, air conditioning, toys, and optional gear can reduce stability margins. Good designers leave enough reserve for real-world cruising loads.

Typical design intention for this size

6. Practical takeaways