Question details:


The ERS is a document maintained by the ISAF which is a revised on the same 4 year cycle as the Racing Rules of Sailing. The current version may be found on the ISAF website and there are several versions in translation listed there too.

Question details:

What is the difference between a Q&A and a Class Rules Interpretation?


An interpretation is requested when it is not clear (to a designer, builder, measurer, class association or certification authority) how a class rule shall be interpreted. When an interpretation is issued it should be kept in mind that the interpretation is valid until the class rules are changed or for two years maximum only. The purpose of this last rule is that two years gives sufficient time to consider if the effect of the interpretation is a) desirable or b) undesirable. Depending on the decision or choice (a or b, by the IRSA TC or the class depending on whether there is an independent class organisation or not) the class rules can be revised accordingly.

Thus, when drafting any interpretation, it should be kept in mind how the class rules should/could be revised to make the original interpretation request redundant.

It follows that, if no revised class rule can be written, there is no need to issue an interpretation. Where no interpretation is required, but only an explanation of the effect of the class rules, it follows that it would be appropriate to deal with the original request by issuing a Q&A to be published on the IRSA website and elsewhere as appropriate.

This is the guiding principle used by the IRSA Technical Committee when considering any question about the class rules whether it is a formal request for an interpretation or not.


Question details:

At what point, on change of ownership, does the certificate become invalid?


The certificate becomes invalid upon a change of ownership. The change of ownership is the important criterion – not the signing of the certificate by the new owner – not the issue of the new certificate in the new owner’s name.

However, while the concept of ownership is normally well understood between any two people it may be that the law of the land becomes relevant in particular cases and this may vary depending on the contract involved and where the ‘transaction’ takes place.

The view is that IRSA class rules are not intended to, nor do they, shed any light on ownership or when it changes hands.

Question details:

Does an alternative sail have to fit within the profile of the 'largest' measured sail?

The 2002 class rules C.8.1 Limitations stated: "The profile of each alternative sail shall fall within the profile of the sails recorded on the certificate."

Is this no longer a requirement in the 2016 class rules?




Diff Profilesgb1No. Under the 2002 class rules it is required that 'alternative' sails shall fall within the profile of the sails recorded on the certificate. The 2016 class rules do not require this.

Sail makers will be aware that sails are 3D objects and small changes to the inbuilt shape at the seams will have an effect on the profile of the sail. Although apparently simple in its requirements, the 2002 class rule creates several problems. Unless the sailmaker knows the leech length of a sail he is replacing he is unable to make a sail of the same profile (even if it is a purely 2D object). Even 1 mm more, or 1 mm less, leech length or luff curve results in the profile of the replacement sail not matching the original. It is not smart to have a class rule that does not allow the owner to replace his equipment and easily meet the class rules. Further, unless the sails measured and recorded on the certificate are retained by the owner when he has replacement sails they, and the other 'alternative' sails cannot be checked according to the class rules.

The 2016 class rules no longer require alternative sails to fall within the profile of the sails recorded on the certificate but treat the issue in a slightly different way that solves the problems mentioned above and gives other benefits. How?

The way in which the 'largest' sail is placed on the measurement grid has been revised marginally - the head and tack are placed on a line perpendicular to the transverse grid lines with the clew placed on a grid line. At and above the clew the cross widths are taken as usual (but at 200 mm intervals instead). Below the clew the depths are taken at 50 mm intervals. The dimensions are recorded on the certificate.

'Alternative' sails are checked by placing them on the grid in the same way and checking that their dimensions (measured in the same way) are equal to or less than the certificate dimensions.

There is no requirement for these 'alternative' sails to fall within the profile of the 'largest'. This introduces freedom to have sails made with different luff curves (or fullness/camber for example) but which comply with the certificate. Any width added at the luff needs to be removed at the leech. Provided the cross widths measured at all grid lines remain less than or equal to the certifiate values, the sail complies. See the diagram above.

The sail maker has all the information he needs to make sails that comply with the class rules as extended by the boat's certificate without asking for more. At equipment inspection there need be no difficulty in establishing a sail's compliance under the 2016 class rules.

This freedom exists for boats with certificates to the 2016 class rules only. Boats measured to the 2002 class rules and any new sails made for them shall continue to comply with those class rules. 



Question details:

Use of boats with certificates issued by sources other than IRSA affiliated bodies?

Is it possible to enter an event described in the NoR and SIs as for boats of an international class (IOM,. M, 10R or A Class) with a certificate other than an IRSA certificate issued by a body affiliated to IRSA?



The IRSA international classes are distinct from classes using the same name but which are not administered (ultimately) by IRSA. For example the Naviga administered One Metre, Marblehead and Ten Rater classes are different classes and the certificates issued under those rules are not valid for IRSA events (world or continental championships) or events normally organised by IRSA affiliated bodies. The same is true for the Marblehead class administered by the American Model Yachting Association which uses class rules different to the international class rules.

The owner of a boat in one of those classes can obtain a certificate for the international class after having his boat measured to the IRSA class rule. To do this he should find an official measurer (please see the Equipment Rules of Sailing) and then contact his certification authority (normally the body in his country that administer rc sailing and is affiliated to IRSA). If he is a member of a body affiliated to his World Sailing Member National Authority (the body responsible for the administration of SAILING in his country) he will then be eligible to take part in events for the international class.

Question details:


An event can be run using "single certificates"

If it is considered desirable at a particular event to ensure a sailor cannot choose the best configuration to suit the prevailing conditions, the event organiser can issue a Notice of Race, and a Sailing Instruction, requiring a certificate to be lodged at some prescribed time ahead of the event and to use the boat in that configuation. This also prevents owners of multiple boats from choosing which boat to use at the time of the race.


Question details:

Are the sail marks shown below compliant with the RRS as modified by Appendix E?


RRS Appendix E8 G1.4 (a) requires national letters to be in 'capital letters'. The 'K' in this set of letters does not look like a capital letter in the same type face as the 'U' and 'R' so these do not comply.



RRS Appendix E8 G1.4 (a) requires marks to be of the 'same colour'. It also requires them to be 'clearly legible'. These numbers are formed by infilling a black outline with green so they do not comply with the requirement to be of the same colour. They may also fail on legibility because the green is not as opaque/dark as other colours.



This set of national letters fail to comply for the same reason.



RRS Appendix E8 G1.4 (a) requires marks to be 'clearly legible'. Where the body of the sail is a mix of materials of different colours there can be problems choosing a colour for the sail marks that will meet the 'clearly legible' requirement.

Here the owner has used white marks instead of black. Are they 'clearly legible'? Would black sail marks be more 'clearly legible'? If the appointed equipment inspector at an event reports this to the race committee they shall bring a protest against the boat which the jury will decide on. 



RRS Appendix E8 G1.4 (a) requires marks to be 'clearly legible'. The race committee at the world championships in Lake Garda, 2016, complained about marks that had strokes that were relatively thin because they were not very legible at a distance.

The same or better legibility than Helveitica is acceptable. Assuming the standard (not bold, narrow or condensed) font is meant by this the ratio of stroke thickness to height for Helvetica is between 12 and 14% of the height. The example below looks less than this and is likely to be less 'clearly legible'.

P1030960        22


This set of national letters probably fail to comply for the same reason. The gaps created by the use of a stencil do not help.



The vertical spacing of marks is controlled by RRS Appendix E8 G1.5 (a). Where there is sufficient space available on the sail this is currently a minimum of 60 mm.

The example here does not meet that requirement.



The height of marks is controlled by RRS Appendix E8 G1.4 (b) which specifies the height of numbers to be 100 mm mimimum and 110 mm maximum. The variation in these is greater than the permitted variation.

The spacing of marks is controlled by RRS Appendix E8 G1.5 (b) which specifies the spacing of numbers to be 20 mm mimum and 30 mm maximum. The spacing in these is less than 20 mm.



Question details:

What does a race committee do when a boat has sail marks that are not clearly legible or compliant with the RRS?


A little history first - going back a couple of decades the sail identification marks rules were in the class rules and measurers were required to check that marks complied with those rules. In principle this ensured boats had compliant sail identification marks. But in practice, for various reasons, a proportion of boats had marks that did not comply.

Race committees and juries tended to avoid pressing the issue - it was a measurement issue not a racing rules issue and, therefore, not their problem. Taking the sail marks (except for the insignia) out of the class rules solved several problems - most importantly, compliance with the sail marks rules was a racing rules issue and was clearly something the race committee and jury had full and sole responsibility and authority for dealing with. Other problems solved were harmonisation across the classes, the possibility of sail certification (measurement) without application of the numbers and letters, a saving of measurer time when certifying (measuring) sails, and the freedom for the owner to change the sail numbers without having to engage the measurer (something that was rarely done anyway).

A boat that has marks that are not clearly legible infringes RRS App G1.1. There are several other ways that marks may fail to comply with this rule and App E - please see the Q&A under Sail Identification for some examples. In either case the race committee may be affected because it may have difficulty identifying the boat in question during a recall or when finishing. Competitors, umpires and judges may be affected when attempting to protest the boat. This is a fairness issue and, therefore, one which an international jury can be asked to advise on by the race committee (see App N2.1).

In the first instance the race committee, or an equipment inspector or technical committee at a major event, should advise the sailor that his sail marks do not comply with the RRS and that the boat will be protested if it races without suitable amendment to the marks. Hopefully he will respond appropriately. Provision of a black marker pen may help him comply. Provision of acetone to remove inked marks may also be useful. With average care self adhesive numbers can be removed without damaging sails and no are excuse for non-compliance.

If the sailor fails to respond in an appropriate way the race committee or technical committee can (and should) proceed as soon as the boat races as it would for any other breach of the RRS by making a protest against the boat under RRS 60.2/60.4.

When a protest committee finds that a boat has sail identification marks that are not compliant it shall either warn her and give her time to comply or penalise her. See App G4. As the penalty is not prescribed by the RRS it is one that is discretionary i.e. it can be scaled to suit the specific case. International juries will be familiar with the Discretionary Penalties guide - there is one in preparation for RC sailing.











Question details:

The XYZ Club wants to run an event for the ABC Class.  What are the options?


pdfComplete Document as PDF Download

Some definitions are needed first.


Part A.  The XYZ Club wants to know what approvals may be needed.  This is illustrated in the following decision tree.


Part B. The XYZ Club wants to know about the Notice of Race for an event and/or the qualifications required of the Race Officials. This is illustrated in the following decision tree.


Part C. The XYZ Club wants to know about the name of the event. This is illustrated in the following table.


Concluding comments

While it is common to speak about an “international event”, this concept has no direct relevance to the question of approvals, Notice of Race, Race Official qualifications, or event title.

Question details:

In Appendix E8 G.1.5 (b) (4) requires the prefix ‘1’ before a mainsail number only. Why?


This is a drafting error in the Appendix E rule E.8.

The following addition to the Standard Sailing Instructions used by IRSA Members for their events should be made.


1.4  Racing rule E8 will be changed as follows:

Add new G.1.5 (a) (6) ‘with sufficient space in front of the sail number for a prefix ‘1’.’

Delete G.1.5 (b) (4).