ISO 8666:2020 pdf download – Small craft — Principal data.
5.3 Athwartship 5.3.1 General Athwartship dimensions shall be measured as the distance between two vertical planes parallel to the centreplane of the craft when upright. 5.3.2 Maximum beam, B max The maximum beam (B max ) shall be measured in accordance with 5.3.1 between planes tangent through the outermost parts of the craft. The maximum beam includes all structural or integral parts of the craft, such as extensions of the hull, hull/deck joints, extensions such as doublings, sheer planks, chain plates, rubbing strakes, permanent fenders, and liferails extending beyond the craft’s side. For multihulls, B max shall be measured as the beam across the outer hulls. 5.3.3 Beam of hull, B H The beam of the hull (B H ) shall be measured in accordance with 5.3.1 between the outermost permanently fixed parts of the hull. The beam of the hull includes all structural or integral parts of the craft such as extensions of the hull, hull/deck joints, and bulwarks. The beam of the hull excludes removable parts that can be detached in a non-destructive manner and without affecting the integrity of the craft, e.g. rubbing strakes, fenders, liferails and stanchions extending beyond the craft’s side, and other similar equipment. For multihulls, B H shall be measured as the beam across the outer hulls. See Figure 1 for monohull measurements and Figure 2 for multihull measurements.
5.3.4 Beam, waterline, B WL The beam at waterline (B WL ) shall be measured in accordance with 5.3.1 as the maximum distance between the intersection of the hull surface and the flotation plane for a specific loading condition. For multihulls, the beam at waterline shall be established for each hull individually. 5.3.5 Maximum beam, waterline, B WLmax For multihulls only, the maximum beam at waterline (B WLmax ) shall be measured as the waterline beam across the outer hulls. 5.3.6 Beam between hull centres, B CB For catamaran and trimaran, the beam between hull centres (B CB ) shall be measured as the transverse distance between the centres of buoyancy of the outer hulls.