EN ISO 12217-2:2002

SLOVENSKI STANDARD
01-december-2002
0DODSORYLOD±6WDELOQRVWLQRFHQDY]JRQDWHUNDWHJRUL]DFLMD±GHO-DGUQLFHV
WUXSRPYHþMLPDOLHQDNLPP,62
Small craft - Stability and buoyancy assessment and categorization - Part 2: Sailing
boats of hull length greater than or equal to 6 m (ISO 12217-2:2002)
Kleine Wasserfahrzeuge - Festlegung und Kategorisierung von Querstabilität und
Auftrieb - Teil 2: Segelboote ab 6 m Rumpflänge (ISO 12217-2:2002)
Petits navires - Evaluation et catégorisation de la stabilité et de la flottabilité - Partie 2:
Bateaux a voiles d'une longueur de coque supérieure ou égale a 6 m (ISO 12217-
2:2002)
Ta slovenski standard je istoveten z: EN ISO 12217-2:2002
ICS:
47.080
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 12217-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2002
ICS 47.080
English version
Small craft - Stability and buoyancy assessment and
categorization - Part 2: Sailing boats of hull length greater than
or equal to 6 m (ISO 12217-2:2002)
Petits navires - Evaluation et catégorisation de la stabilité et Kleine Wasserfahrzeuge - Festlegung und Kategorisierung
de la flottabilité - Partie 2: Bateaux à voiles d'une longueur von Querstabilität und Auftrieb - Teil 2: Segelboote ab 6 m
de coque supérieure ou égale à 6 m (ISO 12217-2:2002) Rumpflänge (ISO 12217-2:2002)
This European Standard was approved by CEN on 11 March 2002.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2002 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 12217-2:2002 E
worldwide for CEN national Members.

CORRECTED  2002-07-17
Foreword
This document (ISO 12217-2:2002) has been prepared by Technical Committee ISO/TC 188
"Small craft" in collaboration with CMC.
This European Standard shall be given the status of a national standard, either by publication
of an identical text or by endorsement, at the latest by October 2002, and conflicting national
standards shall be withdrawn at the latest by October 2002.
This document has been prepared under a mandate given to CEN by the European
Commission and the European Free Trade Association, and supports essential requirements
of EU Directive(s).
For relationship with EU Directive(s), see informative annex ZB, which is an integral part of
this document.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of
the following countries are bound to implement this European Standard: Austria, Belgium,
Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy,
Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the
United Kingdom.
Endorsement notice
The text of the International Standard ISO 12217-2:2002 has been approved by CEN as a
European Standard without any modifications.
NOTE Normative references to International Standards are listed in annex ZA (normative).
Annex ZA
(normative)
Normative references to international publications
with their relevant European publications
This European Standard incorporates by dated or undated reference, provisions from other
publications. These normative references are cited at the appropriate places in the text and the
publications are listed hereafter. For dated references, subsequent amendments to or revisions
of any of these publications apply to this European Standard only when incorporated in it by
amendment or revision. For undated references the latest edition of the publication referred to
applies (including amendments).
NOTE Where an International Publication has been modified by common modifications,
indicated by (mod.), the relevant EN/HD applies.
Publication Year Title EN Year
ISO 9093-1 1994 Small craft - Seacocks and through- EN ISO 9093-1 1997
hull fittings - Part 1: Metallic
ISO 10240 1995 Small craft - Owner's manual EN ISO 10240 1996
ISO 11812 2001 Small craft - Watertight cockpits and EN ISO 11812 2001
quick-draining cockpits
ISO 14946 2001 Small craft - Maximum load capacity EN ISO 14946 2001
Annex ZB
(informative)
Clauses of this European Standard addressing essential
requirements or other provisions of EU Directives
This European Standard has been prepared under a mandate given to CEN by the
European Commission and the European Free Trade Association and supports essential
requirements of EU Directive 94/25/EC.
WARNING: Other requirements and other EU Directive may be applicable to the
product(s) falling within the scope of this standard.
The following clauses of this standard, as detailed in Table ZB.1, are likely to support
requirements of Directive 94/25/EC.
Compliance with the clauses of this standard provides one means of conforming with the
specific essential requirements of the Directive concerned and associated EFTA
regulations.
Clauses/sub- Corresponding Comments
clauses of this annexes/ paragraphs
European Standard of Directive 94/25/EC
5, 6, 7, 8, Annex A, Annex I, Clause 3.2, Design categories A, B,
B, C Stability and Freeboard, C and D defined in the
Clause 3.5, Flooding, standard are considered
and Clauses 3.6 and 3.2, to correspond to design
maximum load and categories A, B, C and D
number of persons of the Directive
6.7, 7.6, Annex D, E Annex I, Clause 3.3,
Buoyancy and flotation
Annex F Annex I, Clause 2.5,
Owner's manual
INTERNATIONAL ISO
STANDARD 12217-2
First edition
2002-04-01
Small craft — Stability and buoyancy
assessment and categorization —
Part 2:
Sailing boats of hull length greater than
or equal to 6 m
Petits navires — Évaluation et catégorisation de la stabilité et de la
flottabilité —
Partie 2: Bateaux à voiles d'une longueur de coque supérieure ou égale à
6 m
Reference number
ISO 12217-2:2002(E)
©
ISO 2002
ISO 12217-2:2002(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not
be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this
file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat accepts no liability in this
area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters
were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event
that a problem relating to it is found, please inform the Central Secretariat at the address given below.

©  ISO 2002
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic
or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO's member body
in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.ch
Web www.iso.ch
Printed in Switzerland
ii © ISO 2002 – All rights reserved

ISO 12217-2:2002(E)
Contents Page
Foreword.v
Introduction.vi
1 Scope .1
2 Normative references.1
3 Terms and definitions .2
3.1 Primary.2
3.2 Hazards.3
3.3 Downflooding.3
3.4 Dimensions, areas and angles .4
3.5 Condition, mass and volume.5
3.6 Other terms and definitions.7
4 Symbols.9
5 Procedure .10
5.1 Maximum total load .10
5.2 Sailing or non-sailing .10
5.3 Tests, calculations and requirements to be applied.10
6 Requirements for monohull boats .10
6.1 Requirements to be applied .10
6.2 Downflooding.12
6.3 Angle of vanishing stability and minimum mass .14
6.4 Stability index (STIX).16
6.5 Knockdown-recovery test.19
6.6 Wind stiffness test.20
6.7 Flotation requirements.22
6.8 Capsize-recovery test.22
7 Requirements for catamarans and trimarans.23
7.1 Requirements to be applied .23
7.2 Downflooding openings.23
7.3 Downflooding height.23
7.4 Stability information.24
7.5 Warning symbols.24
7.6 Buoyancy when inverted .24
7.7 Breaking waves.25
8 Application .25
8.1 Deciding the design category .25
8.2 Meaning of the design categories (see Table 8) .25
Annex A (normative) Full method for required downflooding height .27
Annex B (normative) Methods for calculating downflooding angle .29
Annex C (normative) Determining properties of the curve of righting levers .31
Annex D (normative) Method for calculating reserve of buoyancy after inversion or flooding .33
Annex E (normative) Flotation material and elements.35
Annex F (normative) Information for owner's manual .37
Annex G (informative) Determining wind heeling information.40
Annex H (informative) Summary of requirements .42
ISO 12217-2:2002(E)
Annex I (informative) Worksheets .45
Bibliography .59

iv © ISO 2002 – All rights reserved

ISO 12217-2:2002(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO
member bodies). The work of preparing International Standards is normally carried out through ISO technical
committees. Each member body interested in a subject for which a technical committee has been established has
the right to be represented on that committee. International organizations, governmental and non-governmental, in
liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical
Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.
The main task of technical committees is to prepare International Standards. Draft International Standards adopted
by the technical committees are circulated to the member bodies for voting. Publication as an International
Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this part of ISO 12217 may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
International Standard ISO 12217-2 was prepared by Technical Committee ISO/TC 188, Small craft.
ISO 12217 consists of the following parts, under the general title Small craft — Stability and buoyancy assessment
and categorization:
 Part 1: Non-sailing boats of hull length greater than or equal to 6 m
 Part 2: Sailing boats of hull length greater than or equal to 6 m
 Part 3: Boats of hull length less than 6 m
Annexes A, B, C, D, E and F form a normative part of this part of ISO 12217. Annexes G, H and I are for
information only.
ISO 12217-2:2002(E)
Introduction
This part of ISO 12217 enables the determination of limiting environmental conditions for which an individual boat
has been designed.
vi © ISO 2002 – All rights reserved

INTERNATIONAL STANDARD ISO 12217-2:2002(E)

Small craft — Stability and buoyancy assessment and
categorization —
Part 2:
Sailing boats of hull length greater than or equal to 6 m
CAUTION — Compliance with this part of ISO 12217 does not guarantee total safety or total freedom of
risk from capsize or sinking.
1 Scope
This part of ISO 12217 specifies methods for evaluating the stability and buoyancy of intact (i.e. undamaged)
boats. The flotation characteristics of boats vulnerable to swamping are also encompassed.
The evaluation of stability and buoyancy properties using this part of ISO 12217 will enable the boat to be assigned
to a design category (A, B, C or D) appropriate to its design and maximum load.
This part of ISO 12217 is applicable to boats propelled primarily by sail (even if fitted with an auxiliary engine) of
6 m up to and including 24 m hull length. However, it may also be applied to boats of under 6 m if they are
habitable multihulls or if they do not attain the desired design category specified in ISO 12217-3 and they are
decked and have quick-draining recesses which comply with ISO 11812.
This part of ISO 12217 excludes
 inflatable and rigid-inflatable boats up to 8 m covered by ISO 6185,
 canoes, kayaks or other boats with a beam of less than 1,1 m.
It does not include or evaluate the effects on stability of towing, fishing, dredging or lifting operations, which should
be separately considered if appropriate.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of
this part of ISO 12217. For dated references, subsequent amendments to, or revisions of, any of these publications
do not apply. However, parties to agreements based on this part of ISO 12217 are encouraged to investigate the
possibility of applying the most recent editions of the normative documents indicated below. For undated
references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain
registers of currently valid International Standards.
ISO 2896:2001, Rigid cellular plastics — Determination of water absorption
1)
ISO 8666:— , Small craft — Principal data
ISO 9093-1:1994, Small craft — Seacocks and through-hull fittings — Part 1: Metallic

1) To be published.
ISO 12217-2:2002(E)
1)
ISO 9093-2:— , Small craft — Seacocks and through-hull fittings — Part 2: Non-metallic
1)
ISO 9094-1:— , Small craft — Fire protection — Part 1: Craft with a hull length of up to and including 15 m
1)
ISO 9094-2:— , Small craft — Fire protection — Part 2: Craft with a hull length of over 15 m
)
ISO 10240:1995 , Small craft — Owner’s manual
ISO 11812:2001, Small craft — Watertight cockpits and quick-draining cockpits
1)
ISO 12216:— , Small craft — Windows, portlights, hatches, deadlights and doors — Strength and tightness
requirements
ISO 14946:2001, Small craft — Maximum load capacity
IMO Resolution MSC.81(70) — Revised Recommendation on Testing of Life-Saving Appliances
3 Terms and definitions
For the purposes of this part of ISO 12217, the following terms and definitions apply. The meanings of certain
symbols used in the definitions are given in clause 4.
3.1 Primary
3.1.1
design category
description of the sea and wind conditions for which a boat is assessed to be suitable by this part of ISO 12217
NOTE See also 8.2.
3.1.2
sailing boat
2/3
boat for which the primary means of propulsion is by wind power, having A W 0,07(m )
S LDC
3.1.3
catamaran
boat with two main load-bearing hulls
EXAMPLE Boats with a centreline or bridge-deck nacelle which supports less than 30 % of the total loaded displacement
mass are considered to be catamarans. Proas are asymmetric catamarans.
3.1.4
trimaran
boat with a centre main hull and two sidehulls in which the centre hull, when the boat is upright, supports 30 % or
more of the total loaded displacement mass
3.1.5
recess
any volume open to the sky that may retain water
EXAMPLE Cockpits, wells, open volumes or areas bounded by bulwarks or coamings.
NOTE Cabins, shelters or lockers provided with closures according to the requirements of ISO 12216 are not recesses.

2) Undergoing revision.
2 © ISO 2002 – All rights reserved

ISO 12217-2:2002(E)
3.1.6
quick-draining recess
recess fulfilling all the requirements of ISO 11812 for “quick-draining cockpits and recesses”.
NOTE 1 According to its characteristics, a cockpit may be considered to be quick-draining for one design category, but maybe
not for a higher one.
NOTE 2 ISO 11812 contains requirements with which most sailing dinghies cannot comply.
3.1.7
watertight recess
recess fulfilling all the requirements of ISO 11812 for “watertight cockpits and recesses”
NOTE This term only implies requirements in respect of watertightness and sill heights, but not those for drainage.
3.1.8
fully decked boat
boat in which the horizontal projection of the sheerline area comprises any combination of
 watertight deck and superstructure, and/or
 quick-draining recesses which comply with ISO 11812, and/or
 watertight recesses complying with ISO 11812 with a combined volume of less than L B F /40,
H H M
all closing appliances being watertight in accordance with ISO 12216.
NOTE The plan area of recesses permitted for boats of design category A or B is restricted by the requirements of 6.1.5.
3.2 Hazards
3.2.1
capsize
event when a boat reaches any heel angle from which it is unable to recover to equilibrium near the upright without
intervention
3.2.2
knockdown
event when a boat reaches a heel angle sufficient to immerse the masthead, and from which it may or may not
recover without intervention
3.2.3
inversion
event when a boat becomes upside down
3.3 Downflooding
3.3.1
downflooding opening
any opening (including the edge of a recess) that may admit water into the interior or bilge of a boat, or a recess,
apart from those excluded in 6.2.1.1
3.3.2
downflooding angle
f
D
angle of heel at which the downflooding openings described in 6.2.1.1 become immersed, when the boat is in calm
water and in the appropriate loading condition at design trim
ISO 12217-2:2002(E)
NOTE 1 Where openings are not symmetrical about the centreline of the boat, the case resulting in the smallest angle is
used. The following are specifically considered:
 f is the downflooding angle to any downflooding opening;
DA
 f is the downflooding angle at which recesses which are not quick-draining begin to fill with water;
DC
 f is the downflooding angle at which any main access hatch (i.e. having an opening area greater than 0,18 m each)
DH
giving direct access to the main open air helm position first begins to become immersed.
NOTE 2 Downflooding angle is expressed in degrees.
3.3.3
downflooding height
h
D
smallest height above the waterline to any downflooding opening, apart from those excluded in 6.2.1.1 when the
boat is upright in calm water and at loaded displacement mass and design trim
NOTE Downflooding height is expressed in metres.
3.4 Dimensions, areas and angles
3.4.1
length of hull
L
H
length of the hull according to ISO 8666
NOTE Length of hull is expressed in metres.
3.4.2
length waterline
L
WL
waterline length measured in accordance with ISO 8666 when the boat is upright in calm water, in the appropriate
loading condition and at design trim
NOTE 1 For multihull boats, this length relates to that of the longest individual hull.
NOTE 2 Length waterline is expressed in metres.
3.4.3
beam of hull
B
H
maximum beam of the hull according to ISO 8666
NOTE 1 For catamaran and trimaran boats, B shall be measured as the maximum beam across the outer hulls.
H
NOTE 2 Beam of hull is expressed in metres.
3.4.4
beam waterline
B
WL
greatest beam measured according to ISO 8666 at the waterline which, for multihull boats, is the sum of the
maximum waterline beams of all hulls, the boat being upright, in the appropriate loading condition and at design
trim
NOTE Beam waterline is expressed in metres.
4 © ISO 2002 – All rights reserved

ISO 12217-2:2002(E)
3.4.5
beam between hull centres
B
CB
on catamaran and trimaran boats, the transverse distance between the centres of buoyancy of the sidehulls
NOTE Beam between hull centres is expressed in metres.
3.4.6
freeboard amidships
F
M
distance of the sheerline or deck above the waterline at L /2 according to ISO 8666, the boat being upright, in the
H
appropriate loading condition and at design trim
NOTE Freeboard amidships is expressed in metres.
3.4.7
draught of the canoe body
T
C
draught of the main buoyant part of the hull(s) below the waterline, as defined in ISO 8666, the boat being upright
in the appropriate loading condition and at design trim
NOTE Draught of canoe body is expressed in metres.
3.4.8
nominal sail area
A
S
nominal projected profile area of sails, as defined in ISO 8666
NOTE Sail area is expressed in square metres.
3.4.9
actual sail area
A¢
S
actual profile projected area of a specific combination of sails
NOTE 1 Sail area is expressed in square metres.
NOTE 2 This area will vary according to the individual sail combination being considered.
3.4.10
angle of vanishing stability
f
V
angle of heel nearest the upright (other than upright) in the appropriate loading condition at which the transverse
stability righting moment is zero; determined assuming that there is no offset load, and that all potential
downflooding openings are considered to be watertight
NOTE 1 Where a boat has recesses which are not quick-draining, f is to be taken as f , unless such recesses are fully
V DC
accounted for in determining f
V.
NOTE 2 Angle of vanishing stability is expressed in degrees.
3.5 Condition, mass and volume
3.5.1
light craft condition
boat equipped as the light craft mass according to ISO 8666 with the following added as appropriate:
a) where provision is made for propulsion by outboard engine(s) of more than 3 kW, the heaviest engine(s)
recommended for the boat by the manufacturer, mounted in the working position(s);
ISO 12217-2:2002(E)
b) where batteries are fitted, they shall be mounted in the position intended by the builder;
c) mast(s), boom(s), and other spar(s) on board and rigged in the stowed position ready for use, but not set; all
standing and running rigging in place;
d) any sails supplied by the builder, onboard and rigged ready for use, but not hoisted, e.g. mainsail on boom,
roller furling sails furled, hanked foresails on stay stowed on foredeck
NOTE In item b), if there is no specific stowage provided for batteries, the mass of one battery for each engine over 7 kW
shall be allowed for, and located within 1,0 m of the engine location.
3.5.2
minimum operating condition
boat in the light craft condition with the following additions:
a) mass to represent the crew, positioned on the centreline near the main control position of
 75 kg where L u 8 m;
H
 150 kg where 8 m < L u 16 m;
H
 225 kg where 16 m < L u 24 m.
H
b) essential safety equipment with a mass of not less than (L - 2,5) kg;
H
c) non-consumable stores and equipment normally carried on the boat;
d) water ballast in tanks which are symmetrical about the centreline and which are notified in the owner’s manual
to be filled whenever the boat is afloat, but no liquid being in ballast tanks which are intended by the builder to
be used for variable asymmetric ballasting whilst under way;
e) a liferaft (where appropriate) fitted in the stowage provided.
Variable position elements (e.g. canting keels, movable solid ballast, tilting masts) shall be positioned symmetrically
about the centreline of the boat;
Any centreboard or keel shall be in the raised position unless it can be fixed in the lowered position and an
appropriate instruction is given in the owner’s manual.
3.5.3
minimum operating mass
m
MOC
mass of the boat in the minimum operating condition
NOTE Minimum operating mass is expressed in kilograms.
3.5.4
maximum total load
m
MTL
maximum load which the boat is designed to carry in addition to the light craft condition, comprising the
manufacturer’s maximum recommended load as defined in ISO 14946, including all liquids (e.g. fuel, oils, fresh
water, water in ballast or bait tanks and live wells) to the maximum capacity of fixed or portable tanks
NOTE Maximum total load is expressed in kilograms.
6 © ISO 2002 – All rights reserved

ISO 12217-2:2002(E)
3.5.5
loaded displacement condition
boat in the light craft condition with the maximum total load added so as to produce the design trim, the vertical
distribution of crew mass being that described in C.2.2
3.5.6
loaded displacement mass
m
LDC
mass of the boat in the loaded displacement condition
NOTE Loaded displacement mass is expressed in kilograms.
3.5.7
displacement volume
V
D
volume of displacement of the boat that corresponds to the appropriate loading condition, taking the density of
water as 1 025 kg/m
NOTE Displacement volume is expressed in cubic metres.
3.6 Other terms and definitions
3.6.1
calculation wind speed
v
W
wind speed used in calculations
NOTE Calculation wind speed is expressed in metres per second.
3.6.2
crew
collective description of all persons onboard a boat
3.6.3
crew limit
CL
maximum number of crew (with a mass of 75 kg each) used when assessing the design category
3.6.4
design trim
longitudinal attitude of a boat when upright, with crew, stores and equipment in the positions designated by the
designer or builder
3.6.5
flotation element
element which provides buoyancy to the boat and thus influences the flotation characteristics
3.6.5.1
air tank
tank made of hull construction material, integral with hull or deck structure
3.6.5.2
air container
container made of stiff material, not integral with the hull or deck structure
ISO 12217-2:2002(E)
3.6.5.3
low density material
material with a specific gravity of less than 1,0 primarily incorporated into the boat to enhance the buoyancy when
swamped
3.6.5.4
inflated bag
bag made of flexible material, not integral with hull or deck, accessible for visual inspection and intended always to
be inflated when the boat is being used
NOTE Bags intended to be inflated automatically when immersed (e.g. at the masthead as a means to prevent inversion)
are not regarded as flotation elements.
3.6.6
inclining experiment
method by which the vertical position of the centre of gravity (VCG) of a boat can be determined
NOTE 1 The VCG, together with a knowledge of the shape of the hull (the lines plan) and the position of the waterline in a
known loading condition, enable all the intact stability parameters to be calculated.
NOTE 2 For a full description of how to conduct an inclining experiment, standard naval architecture textbooks should be
consulted (e.g. Principles of Naval Architecture, published by S.N.A.M.E) or refer to American Society for Testing and Materials
Standard Guide for Conducting a Stability Test (ASTM F-1321-90).
3.6.7
righting moment
RM
at a specific heel angle in calm water, the restoring moment generated by the transverse offset of the centre of
gravity of the boat from the centre of buoyancy of the submerged part of the hull
NOTE 1 The righting moment varies with heel angle and is usually plotted graphically against heel angle. Righting moments
are most accurately derived by computer from a knowledge of the hull shape and the location of the centre of gravity. Other
more approximate methods are also available. The righting moment varies substantially with hull form, centre of gravity position,
boat mass and trim attitude.
NOTE 2 Righting moment is expressed in newton metres.
3.6.8
righting lever
GZ
distance in both the horizontal and transverse planes between the centre of buoyancy and the centre of gravity
NOTE Righting lever is equal to the righting moment divided by the product of mass, expressed in kilograms, and
acceleration due to gravity (9,806 m/s ) and is expressed in metres.
3.6.9
loaded waterline
waterline of the boat when upright at loaded displacement mass and design trim
3.6.10
watertightness degree
degree of watertightness as specified in ISO 11812 and ISO 12216
NOTE The degree of watertightness is summarized as follows.
Degree 1: Degree of tightness providing protection against effects of continuous immersion in water.
Degree 2: Degree of tightness providing protection against effects of temporary immersion in water.
Degree 3: Degree of tightness providing protection against splashing water.
Degree 4: Degree of tightness providing protection against water drops falling at an angle of up to 15° from the vertical.
8 © ISO 2002 – All rights reserved

ISO 12217-2:2002(E)
4 Symbols
For the purposes of this part of ISO 12217, symbols and associated units in Table 1 apply.
Table 1 — Symbols
Symbol Unit Meaning
φ degree (°) Angle of heel
φ degree (°) Actual downflooding angle, see 3.3.2
D
φ degree (°) Required downflooding angle, see 6.2.3
D(R)
φ degree (°) Downflooding angle to any downflooding opening
DA
φ degree (°) Downflooding angle to cockpits that are not quick-draining according to ISO 11812
DC
φ degree (°) Downflooding angle to any main access hatchway
DH
φ degree (°) Angle of heel at which maximum righting moment or lever occurs
GZmax
φ degree (°) Angle of vanishing stability, see 3.4.10
V
φ degree (°) Required angle of vanishing stability, see 6.3
V(R)
A m◊degree Positive area under righting lever curve, see 6.4.2
GZ
A m Nominal sail area according to ISO 8666, see 3.4.8
S
A′ m Actual profile projected area of a specific combination of sails, see 3.4.9
S
B m Beam between centres of buoyancy of sidehulls, see 3.4.5
CB
B m Beam of hull according to ISO 8666
H
B m Beam waterline in the appropriate loading condition according to ISO 8666 and 3.4.4. In the case
WL
of multihulls, this is the sum of the waterline beam of each of the hulls.
CL Crew limit = maximum number of persons on board, see 3.6.3
F m Freeboard amidships at the appropriate loading condition according to ISO 8666
M
m Transverse metacentric height
GM
GZ m Righting lever = righting moment (N◊m)/[mass (kg) ¥ 9,806], see 3.6.8
GZ m Righting lever at 90° heel
′
h m Height of centre of area of A above waterline at the appropriate loading condition
S
CE
h m Actual downflooding height, see 3.3.3
D
h m Required downflooding height, see 6.2.2
D(R)
h m Height of waterline at the appropriate loading condition above centre of area of immersed profile
LP
including keel and rudder(s)
L m Length base size = (2L + L )/3
BS WL H
LCG m Longitudinal position of the centre of gravity from a chosen datum
L m Length of hull according to ISO 8666
H
L m Length of waterline at the appropriate loading condition according to ISO 8666
WL
m kg Mass of the boat in the appropriate loading condition
m kg Mass in light craft condition, see 3.5.1
LCC
m kg Loaded displacement mass, see 3.5.5 and 3.5.6
LDC
m kg Mass in the minimum operating condition, see 3.5.2
MOC
m kg Mass of the maximum total load, see 3.5.4
MTL
RM N◊m Righting moment, see 3.6.7
STIX — Actual stability index value at the appropriate loading condition according to 6.4
STIX — Required stability index value, see 6.4.9
(R)
ISO 12217-2:2002(E)
Symbol Unit Meaning
T m Draught of canoe body at the appropriate loading condition according to ISO 8666
C
VCG m Vertical position of the centre of gravity
V m Displacement volume, see 3.5.7
D
V m Volume of a non-quick-draining recess, see normative annex A
R
v m/s Calculation wind speed, see 3.6.1
W
x m Longitudinal distance of downflooding opening from nearest end of boat
D
′
x m Longitudinal distance of downflooding opening from nearest end of boat
D
y m Transverse distance of downflooding opening from periphery of boat
D
y′ m Transverse distance of downflooding opening off centreline
D
z m Height above waterline of downflooding opening
D
5 Procedure
5.1 Maximum total load
Decide on the crew limit and the maximum total load that the boat is intended to carry in accordance with the
definitions. The crew limit shall not exceed that determined by the seating or standing space requirements of
ISO 14946.
It is important to ensure that the maximum total load is not underestimated.
5.2 Sailing or non-sailing
2/3
Confirm that the boat is defined as sailing. Sailing boats are those where A W 0,07 ¥ (m ) .
S LDC
Other boats are non-sailing boats and should be assessed using ISO 12217-1.
5.3 Tests, calculations and requirements to be applied
Clause 6 shall be applied to monohull sailing boats.
Clause 7 shall be applied to catamaran or trimaran sailing boats.
All the requirements of the option chosen from clause 6 or 7 shall be satisfied.
6 Requirements for monohull boats
6.1 Requirements to be applied
6.1.1 Monohull sailing boats shall comply with all the requirements of any one of seven options according to
amount of flotation and decking, and whether the boat is fitted with suitable recesses. These options and the tests
to be applied are given in Table 2.
6.1.2 The design category finally given is that for which the boat satisfies all the relevant requirements of any
one of these options.
6.1.3 For boats using option 1 or 2, the requirements shall be satisfied in the minimum operating condition unless
otherwise specifically noted. If the ratio of m /m exceeds 1,15 then all the requirements shall be satisfied in
LDC MOC
the loaded displacement condition as well as in the minimum operating condition. In calculating the position of the
overall centre of gravity in the loaded displacement condition, the following shall be observed:
 fuel and water shall be located in the fixed tanks;
10 © ISO 2002 – All rights reserved

ISO 12217-2:2002(E)
 provisions shall be stowed in an appropriate location;
 the mass of additional crew (crew limit less those required for m ) shall be added at sheerline height at the
MOC
mid-length of L .
H
6.1.4 Boats using option 1 or 2 and fitted with provision for asymmetric ballasting whilst under way (whether
liquid or solid) shall
a) comply with all the requirements of the selected option as indicated in Table 2, and
b) comply with the requirements of 6.2.3, 6.3 (if appropriate) and 6.4 for the next less demanding design category
considering that the movable ballast is of whichever amount or position that gives the most adverse result
when considering each individual stability requirement.
6.1.5 Recesses of boats to be assigned design category A or B using option 1 of Table 2 shall comply with the
plan-area limitations given below, unless specific account is taken of the mass and free-surface effect of water that
recesses may contain when calculating the stability characteristics.
If this special calculation option is used, righting levers shall be calculated assuming that each recess is treated as
though it had no drainage and is assumed to initially hold water to the following percentage of its maximum
(upright) capacity:
Percentage full = (60 – 240 F/L )
H
where F is the minimum freeboard to the coaming of the recess in question.
Such water shall be assumed to spill out as the boat heels, the righting moments being assumed to be symmetrical
about the upright.
For design category A: plan area of all recesses (m ) < 0,2L B
H H
plan area of all recesses forward of L /2 (m ) < 0,1L B
H H H
For design category B: plan area of all recesses (m ) < 0,3L B
H H
plan area of all recesses forward of L /2 (m ) < 0,15L B
H H H
Table 2 — Requirements to be applied to monohull sailing boats
Option 1 2 3 4 5 6 7
Categories possible A and B C and D C and D C and D C and D C and D C and D
Decking or covering Fully Any Any Any Any Any Any
a
decked amount amount amount amount amount amount
Downflooding openings 6.2.1 6.2.1 6.2.1 6.2.1 6.2.1 6.2.1
Downflooding-height test 6.2.2 6.2.2 6.2.2 6.2.2
Downflooding angle 6.2.3 6.2.3
Angle of vanishing stability 6.3 6.3
Stability index 6.4 6.4
Knockdown-recovery test  6.5 6.5
Wind stiffness test   6.6 6.6
Flotation requirements  6.7 6.7
Capsize recovery test    6.8
a
This term is defined in 3.1.8.
ISO 12217-2:2002(E)
6.2 Downflooding
These requirements are to ensure that a level of watertight integrity appropriate to the design category is
maintained.
6.2.1 Downflooding openings
6.2.1.1 The requirements given below, and in 6.2.2 and 6.2.3, shall apply to all downflooding openings except:
a) watertight recesses with a combined volume less than L B F /40, or quick-draining recesses;
H H M
b) piped drains from quick-draining recesses or from watertight recesses which, if filled, would not lead to
downflooding or capsize when the boat is upright;
c) non-opening appliances;
d) opening appliances located in the topsides which comply with ISO 12216 to tightness degree 2 and which are
referenced in the Owner’s Manual and are clearly marked “WATERTIGHT CLOSURE – KEEP SHUT WHEN
UNDER WAY”; and which are
1) emergency escape hatches or appliances fitted with screwed closures, or
2) in a compartment of such restricted volume that, even if flooded, the boat satisfies all the requirements, or
3) in a boat of design category C or D and which, when at loaded displacement mass, would not sink if the
affected compartment was flooded
...