SCHRS System and Rules
LEGEND: New and Updated material Historic, Archive material
A. GENERAL
A.1 Authority
These regulations are published under the authority of the ISAF.
A.2 Official language
The official language of these regulations is English. In the event of a dispute, the English text shall prevail over any translation.
The word shall is mandatory and the word may is permissive.
A.3 Amendments
The ISAF has the right to amend these regulations if necessary.
A.4 Interpretations
Any interpretations shall be made by the ISAF.
A.5 Spirit of the regulations
In case of doubt about any part of these regulations, the meaning, i.e. the spirit of the regulations governs.
A.6 Limits
Notwithstanding anything contained in these regulations, the ISAF or a National Authority shall have the power to refuse to grant, or withdraw, the status of recognized Class or a rating certificate from any Multihull, giving reasons in writing for taking such action.
A.7 Responsibility
The ISAF does not accept any legal responsibility in respect of these regulations.
B. ADMITTANCE
B.1 Quality of boats
These rules are created for production boats.
Non-productions catamarans, experimental boats and new types with provisional rating shall be ranked apart.
B.1.1 Production boats
- • A production boat belongs to a registered class or to a registered type.
- • The qualification of registered class or registered type requires the following conditions:
- 1. To respect the safety requirements of the government having jurisdiction;
- 2. To produce a minimum of 10 boats;
- 3. To have published class rules (effective for new types after 01/06/2001) which include data as follows:
- WS - Minimum sailing weight.
- CM - Maximum mainsail area.
- VLM - Maximum VLM.
- CJ - Maximum Jib Area.
- VLJ - Maximum VLJ.
- CSPI - Maximum Spinnaker area.
- CB - Maximum Board area.
- VLB - Maximum Board depth below hulls.
- BEAM - The maximum beam of the boat.
- NUMTRAP - The number of crew using trapeze.
- 4. To present the boat in a boatshow.
- 5. To present the boat at the nautical press.
B.1.2 Non-production or experimental boats
- A non-production boat is any boat which does not belong to a registered class or to a registered type. A boat built as a registered boat but which is modified in such way that she contravenes her class rules will be considered as a non-production boat.
B.2 Rating certificate
To be permitted to race, a boat shall provide a rating certificate issued by the ISAF or a National Authority.
The certificate will state the rating as well as relevant datas concerning the boat and the owner.
The rating certificate is obtained as follows:
- • The owner shall have a certificate of origin or a measurement form completed by a recognized measurer.
- • The owner applies to the appropriate National Authority for a rating certificate.
- • The Rating Certificate is not invalidated by change of ownership, providing the data remains constant.
- N.B. A National Authority may require a fee.
C. RATING
C.1 Principle
Ratings, (i.e. time dividing factors,) take as basis measurable datas, warranted by classes, builders or importers, and are calculated using the IOMR formulas described as follows, verifiable by anyone.
C.2 Datas
The measurable datas are as follows:
- WC Weight of the crew (for calculation purposes only).
- WS Minimum weight of the catamaran in sailing conditions.
- AL Maximum overall length.
- WL Maximum waterline length.
- CM Maximum authorised mainsail area.
- VLM Maximum vertical projection of the luff of the mainsail.
- CJ Maximum authorised jib area.
- VLJ Maximum vertical projection of the luff of the jib.
- CSPI Maximum authorised spinnaker area.
- CB Maximum authorised board area.
- VLB Maximum board depth below the hulls.
- BEAM Maximum beam of the boat.
- NUMTRAP Maximum number of crew using trapeze.
C.3 Formulas
All the following formulas use metric units.
C.3.1 Rated Measurements
- Rated Length (after Jan 1st 2007) L = AL
- Rated Length L (before Jan 1st 2007) = WL + 0.3(AL - WL)
- Rated Weight W = WS + WC
- Rated Sail Area A = M + J
- Rated mainsail Area M = CM x ME
- Rated Jib Area J
- Multihulls without spinnaker J = CJ x JE
- Multihulls with spinnaker J =(CJ x JE) + 10% x (CSPI - CJ)
- ME = Mainsail efficiency*
- JE = Jib efficiency*
- * Sail efficiency (%):
- where:
- and:
C.3.2 Intermediate calculations
C.3.3 Corrections and Penalties
- Board Correction
- in which 0.6 is a coefficient and 2 a constant
C.3.4 Power Factor
- where:
- Heeling moment
- Righting moment
C.3.5 Rating (or Time Dividing Factor)
- where rating will be calculated to 3 decimal places
D. MEASUREMENT
All measurements must be done according to the ISAF measurement rules and instructions.
Lengths shall be in metres to three decimal places, areas shall be given in square metres to two decimal places, weights shall be in kilograms.
For "Formula" type classes such as Formula 16, Formula 18, Formula 20 and A-Class, the rating is to reflect the limiting values for all relevant measurements permitted by the class rules. Where a measurement is required by SCHRS but not governed by class rules it is necessary to carry out measurement as required for an SCHRS rating.
D.1 WC : Weight of the crew
A constant 75 kg per crew member.
D.2 WS : Minimum weight of the catamaran in sailing conditions
- • The sailing weight is the weight of the catamaran ready to sail, excluding personal equipment, such as buoyancy aids or trapeze harnesses.
- • The boat itself, and all gear and sails weighed, should be in a dry condition. If this is not possible every effort should be made to dry the items as much as possible, and then the measurer should apply a correction for the weight of the remaining water.
- • All "normal" and "reasonably sized" sheets and lines used for sailing are to be included, if always carried.
- • Paddles are to be included, if always carried.
- • Other items, if always carried, will be included, or a fraction of the weight thereof included, in the WS measurement at the discretion of the measurer, who will also decide what is "normal" and "reasonably sized"
- • A maximum of 10kg of corrector weights, in accordance to the class rules if applicable, may be used to bring the weight up to the WS.
D.3 AL : Maximum Overall Length
The horizontal distance between the forwardmost point on the hull proper, to the aftmost point on the hull proper (normal rudder fittings to be excluded).
D.4 WL : Maximum Waterline Length
To be measured with the boat at sailing weight WS plus crew weight WC. For transom sterned boats, the added weight WC will be distributed until both transoms just touch the water. Other boats will be measured with the weight distributed so that the waterline is parallel to the sailing weight waterline.
D.5 CM : Maximum Authorized Mainsail Area
Maximum mainsail area allowed by the class rules or, in default, registered by the builder. CM includes spars, if mast rotates. (ISAF measurement rules and instructions).
D.6 VLM : Maximium Vertical projection of the Luff of the Mainsail
To be measured along the aft side of the mast, between two bands. When sailed, the mainsail head shall not be hoisted higher than the bottom of the upper band, and the tack point shall not be downhauled lower than the top of the bottom band. For classes or types which have no requirement in their class rules for a lower black band, the VLM will be measured by hoisting the sail and downhauling it just enough to take out any creases, and then measuring the sail from the top of the headboard to a point on the aft side of the mast which is at right angles to the lowest part of the sail.
D.7 CJ : Maximum authorized Jib Area
Maximum Jib area allowed by the class rules or, in default, registered builder.
D.8 VLJ : Maximum Vertical projection of the Luff of the Jib
To be measured along the forward side of the mast.
D.9 CSPI : Maximum authorized Spinnaker area
Asymetrical spinnakers are allowed.
The half width, i.e. the distance between the half leech points shall be greater or equal to 75% of the foot length.
Where SF = foot; SL1 = luff; SL2 = leech; SMG = half width
Stiffening devices such as headboards and battens are prohibited.
Stiffening devices such as headboards, battens, and leech lines are prohibited.
IYRR 50.2 does not apply.
Spinnaker boom/pole. The outermost part of the spinnaker boom or pole shall not come beyond 0.80m from the outermost point of the hulls at deck level.
D.10 CB : Maximum authorized Board area
Useful side area of the board below the hull.
D.11 VLB : Maximum Board depth below the hulls
D.12 BEAM : Maximum beam of the boat.
The maximum width of the boat, including wings, racks, sliding seats or other appendages.
D.13 NUMTRAP : Maximum number of crew on trapeze
E. RACING RESULTS
E.1 Corrected time
The racing results are calculated by dividing the sailing time by the rating (or time dividing factor) to obtain corrected time.
E.2 One-design classes and subgroups
As mentioned in the preamble, National Authorities or organisers may consider separate arrangements or rankings with one-design or level rating classes or subgroups present in sufficient numbers.
E.3 Non-production or experimental boats
Non-production or experimental boats shall be ranked apart.
E.4 Boats sailing under provisional rating
Boats sailing under provisional rating shall be ranked apart.
F. ATTRIBUTION
F.1 Competence
Ratings are assigned by the ISAF, according to the report of the measurer officially recognised by the ISAF or a National Authority.
F.2 Existing types
For existing types which comply with the production boat qualifications, classes and builders shall register each type a standard form giving the data mentioned at paragraph C.2. The ISAF will assign for each a rating which will be valid from the first of January each year.
F.3 Approval of a new type
To get a rating for a new type, a class or builder shall register a standard form giving the data mentioned in paragraph C.2., so that the ISAF can compute a provisional rating.
The ISAF will send the class or builder measurement forms in sufficient number.
As soon as the conditions required to be considered as a production boat are completed (see paragraph B.1.1.), the ISAF may publish a list of updates which become effective on the date of issue unless otherwise stated.
G. VALIDITY
G.1 Issue
Each year, after the November meeting of the ISAF, it will issue a list of ratings which will be valid from the 1st of January of the following year, unless otherwise prescribed by the ISAF or a National Authority.
During the year, the ISAF may publish lists of updates which will become effective at the date of issue unless otherwise stated.
G.2 Builders liability
It is the builder's or his representative's inescapable responsibility to ensure that his hulls, spars, sails, foils and equipment comply with the class rules and these rules at the time of delivery and that alterations to the product are registered with the ISAF before being produced.
G.3 Adjustments
When dimensions of a design are found to differ substantially form the original measurements, the ISAF can decide to alter the original rating to a more penalising one.
Deviation from the maximum and minimum dimensions in one or other direction from the data given on the official lists will never lead to a change to a less penalising rating.
If a class has a rule change or any development which may influence the SCHRS rating then its rating is to be recalculated on the new basis and the number published as appropriate.
G.4 Provisional ratings
Provisional ratings are assigned by the ISAF (see paragraph E.3.).
H. CONTROL
H.1 Inspection or measurement during a regatta
A race committee or a National Authority has the right to conduct an inspection or a measurement during a regatta to check the compliance with the class rules and with these rules.
H.2 Identification marks
Catamarans of recognised classes or registered types shall carry identification marks, indicating the type of catamaran on hulls and sails.
H.3 Responsibility of the owner or his representative
It is the owner's or his representative's inescapable responsibility to ensure that his hulls, spars, sails, foils and equipment comply with the rules of the class in which he enters and these rules at all times, and that alterations, replacements or repairs to the hulls, spars, sails, foils and equipment do not contravene the class rules and these rules and are reported to the measurement form.
New or altered sails shall be measured by a measurer who shall mark the sail near the tack. The National Class Association or the National Authority shall issue a new certificate.
It is the owners or his representative’s responsibility to ensure that their boat conforms to the current rating certificate.
H.4 Rule compliance
In case of a measurement dispute in respect of hulls, spars, foils, sails, battens, type of fittings or equipment and the placing of the same if controlled by these regulations, the following procedures shall be adopted:
- • A sample of ten boats of the same class shall be taken at random and measured by the same identical techniques.
- • The dimensions of the disputed boat shall be equal to, or between the maximum and minimum dimensions obtained from the ten sample boats.
- • If the protested boat is outside these dimensions, the matter, together with any relevant information shall be referred to the chief measurer of the National Authority under whose jurisdiction the race takes place, who shall give a ruling.
H.5 Responsibility of the measurer
A measurer shall not measure hulls, spars, sails, foils or equipment built by himself, or in which he is an interested party or has a vested interest.