In our inaugural International Class Association world council meeting, John Tushingham provided this insightful perspective on the class rules:
One of the founding principles of the rules is that when you purchase a stock boat, pull it out of the box, rig it according to the instructions, then you should be able to go to any event and be competitive and class legal. What we also don’t want to see is an environment were people feel they need to do extra changes to be competitive. The rules aim to ensure that a standard specification boat is always completely competitive. The rules are there, in part, to help support our inclusive founding principles.
John Tushingham
Many of you will be aware of the various social media groups for the classes and how there are many people who try hard to help a newcomer with a rules enquiry but often only succeed in getting lots of other people involved with the usual outcome being somewhat unsatisfactory for all.
The purpose of this page is to give everyone an easy to access to offical class rules interpretations, and outline the procedure that should be used to seek guidance and clarification on current rules.
Requesting an Interpretation
The DF ICA Regulations document outlines the process for requesting a rules interpretation. Head to section 9 and check out section 9.1.1 which gives you the correct way to get in touch with the Rules Sub-Committee and also tells you how your enquiry will be dealt with. It does not give you a timescale, however it might be reasonable for the sub-committee to meet once a month and issue interpretations as they are made.
The usual route to the Rules Sub-committee is in the first instance via your country body, secretary, or world-council member (NCA, DNM NCA, or NCS), who will then follow the procedure set out in the regulations to request an interpretation.
Section 9.2 is for emergency use only and is very much at the discretion of the committee as to whether they accept your personal approach to them. An appropriate example may be the need for a quick clarification during a major event.
Current Interpretations
The ICA Class Rules Sub-committee is responsible for issuing class rules interpretations. The Interpretations are published below.
DF Classes Rules Interpretation April 2026
Issue Date: 22nd April 2026
1. Jib Boom Attachment (Rule Section H)
Submitted by World Council member Sweden
Background: On both DF65 and DF95, many of our members, especially those who are a little older, have difficulty connecting the jib boom to the hull. This problem arises especially when the rig must be changed during a race as fast as possible. The problem is the difficulty to thread the Jib Boom hook-down through the two Deck eyes and attach it to the Deck Eye 4, the hook. Sometimes it takes so long that you miss a race. And it is not only elderly sailors who have this problem, it can also be difficult for younger and more dexterous sailors.
Question: Is it permissible to modify the jib boom attachment to the hull by using a permanent hook and Dyneema loop system to facilitate easier rigging, rather than threading the jib hook-down through the deck eyes as described in the Licensed Builder’s Rigging Instructions?
Interpretation:
No. Pursuant to the DF65 and DF95 Class Rules, Section H, the rig must be assembled and attached as described in the Licensed Builder’s Rigging Instructions. The introduction of hooks, lines, or hardware not specifically listed in the rules or provided in the standard kit constitutes a modification that is not permitted under the “closed” nature of these class rules.
Strict compliance is required for the boat to be considered in-class for international competition. Note to Competitors and Race Officials: While strict compliance is required for international events, the Rules Committee recognises the importance of inclusion and accessibility within the class. For guidance regarding “non-performance” ergonomic adaptations please refer to the Companion Guide: Ergonomic and Accessibility Modifications issued concurrently with this interpretation.
2. Sheet Attachment and Routing (Rule Section G)
Submitted by World Council member Sweden
Question: May the jib and main sheets be permanently attached to the Winch Line Clip, bypassing the standard threading through deck eyes or specific attachment points, to allow for faster/easier rig changes?
Interpretation:
No. The DF65 and DF95 Class Rules require that all running rigging be routed and attached strictly in accordance with the Licensed Builder’s Rigging Instructions. The sheets must pass through the specified deck eyes and be attached to the winch line as illustrated in the official manuals.
Bypassing these points or altering the attachment method constitutes a modification to the sheeting geometry and is not permitted in sanctioned one-design competition.
3. Backstay Termination Hardware (Rule F.5)
Submitted by World Council member Sweden
Question: Is the use of a metal or plastic ring at the end of the backstay (to facilitate connection to the transom hook) permitted in both the DF65 and DF95 classes?
Interpretation:
Yes. The Rules Committee (RC) acknowledges a textual inconsistency between the current DF65 and DF95 Class Rules regarding backstay termination hardware. While DF65 Rule F.5 explicitly permits the use of a ring or plastic bead, the current DF95 Rule F.5 is less specific.
It is the interpretation of the RC that the rigging standards for the backstay should be harmonised across both classes to ensure consistency and ease of use for all competitors. Therefore, the hardware permitted for the DF65 – specifically cord, a bowsie, a ring, a plastic bead, and a hook – is also permitted for use on the DF95.
This interpretation serves to bridge the existing gap in the rulebooks and provides immediate clarity for measurers and sailors. The MC confirms that this discrepancy has been noted for administrative cleanup and will be formally rectified in the next scheduled release of the DF95 Class Rules to ensure both sets of documentation are identical in their allowances.
4. Sail Material Consistency (Rule Section G/H – Sails)
Submitted by DFICA Executive
Question: If a single sail within a rig suite (either the Jib or the Mainsail) is damaged and requires replacement, is it permissible to replace only that sail with another of the same material specification? Or does the rule stating both sails “shall be constructed from the same ply” mandate that they be cut from the same physical batch/roll of material at the same time, thereby requiring a full suite replacement?
Interpretation:
Yes, it is permissible to replace a single sail. The requirement that both the Jib and Mainsail in a suite “shall be constructed from the same ply” is intended to ensure identical weight, stretch, and performance characteristics across the entire rig.
This rule does not mandate that the sails be cut from the same physical roll or manufacturing batch. A sailor may replace a damaged sail provided the replacement is made from material of the same technical specification (same weight, film thickness, finish, and construction) as the remaining sail in the suite.
Criteria for Compliance:
- Performance Identity: The replacement sail must possess the same performance characteristics as the sail it replaces.
- Visual and Physical Consistency: If the Jib and Mainsail are visibly different – such as having different weights, different finishes, or being made of woven cloth of different manufactured colour/weaves – they shall not be considered to be of the “same ply.”
In such cases of clear material discrepancy, the boat will be considered non-compliant with the one-design sail regulations. If the material is technically identical in specification, the replacement is fully permitted.
Companion Guide: Ergonomic and Accessibility Modifications
Document Ref: CG-001 (Ergonomics, Accessibility & Inclusion)
Status: Non-Binding Advisory Note for Local/National Events
Administrative Status
This guide is provided for advisory purposes only and does not constitute an official Class Rules Interpretation. It is intended to offer specific guidance to Local Class Measurement Groups and Race Officers regarding Ergonomics and Accessibility modifications at the local club, state, and national levels.
Alignment with Constitution and Founders’ Statement
The DF Class Association was established with a primary mission to provide affordable, accessible, and inclusive racing. The Founders’ Statement emphasises a class that “encourages participation across all ages and physical abilities.”
To remain true to the Class Constitution, which seeks to grow the sport and minimise barriers to entry, this committee views modifications made specifically for accessibility and ergonomic support – such as simplified jib boom attachments – not as “cheating,” but as essential tools that allow sailors with reduced dexterity or physical limitations to remain active in the fleet. The committee emphasises that such allowances should be assessed on an individual sailor basis, ensuring the modification is a necessary response to a specific accessibility requirement rather than a general fleet-wide deviation from the rules.
Rationale: Accessibility vs. Performance
The committee makes a clear distinction between Performance Modifications (which are strictly prohibited) and Accessibility Aids. The use of a hook or loop system for a jib boom is a “non-performance” adaptation.
- It provides an ergonomic benefit for ease of use on the bank.
- It provides no competitive advantage, mechanical benefit, or speed increase once the boat is on the water.
The committee draws a parallel to established practices in full-sized one-design dinghy classes (such as the ILCA/Laser or Hobie Cat). In those fleets, it is common and widely accepted for sailors to add “righting ropes” or additional grab lines to assist older or less mobile sailors in re-entering or righting the boat after a capsize.
Guidance for Competitors and Officials
- International Events: Strict compliance with the official Interpretation (DF-2026-01) is required. At International Championship levels, the boat must be rigged exactly as per the Class Rules and Licensed Builder’s Instructions.
- Club, State, and National Level: Where a modification is clearly made to support accessibility and inclusion, Race Officials are encouraged to permit the entry. The goal is to see the sailor on the water rather than frustrated on the bank.
Protest Handling: If a sailor is protested for an ergonomic accessibility aid at a non-international event, the Committee recommends a Discretionary Penalty (DP) of zero points. The sailor should be advised that the modification is accepted for local inclusion but must be removed for selected National/International/World level competition to meet strict measurement standards.
DF Classes Rules Interpretation September 2024
The following three questions were raised via the French DF95 Class Association:
Question 1: Is it possible to assemble the jib luff tabling pocket for the forestay by sewing or/and double sided tape and sewing?
Answer: Yes.
Reason: “Tabling” is defined in ERS (G.6.3), and the DF measurement committee supports this definition. A fold and sewing are covered under this definition. However, the fold dimensions must fit within the 12mm band defined in the class rules. It should be noted that while sewing may be appropriate for woven cloth, it is generally not recommended for monofilm due to the potential for reduced integrity and added complexity from the holes. The rules committee may consider revising future rules to prohibit the sewing of monofilm to guide participants towards a good solution.
Question 2: Is it possible to apply a reinforcement patch with double sided tape? If yes, does the double sided tape count as one layer?
Answer: No. Material and double sided tape is not allowed for reinforcement patches.
Reason: The Class rules reference “self adhesive material”. The class rules call for the use of commonly available self adhesive material that may be quickly cut and applied. This has been selected to simplify sail construction. Using extra layers and parts moves away from this goal.
Question 3: Is it possible to reinforce the mainsail luff attachment point with a little piece of wire inside the patch?
Answer: No.
Reason: Metal may optionally be used for sail reinforcement but only when used as an “Eyelet”. Eyelets are round. Although the method explained is an elegant method, as the rules are currently written, it’s not allowed. It should be noted that most aftermarket sails are constructed today without metal eyelets along the luff midpoint position. A reinforced hole without an eyelet usually suffices, and also reduces construction time and cost.
DF Classes Rules Interpretation April 2024
Q: The DF Class rules show a mainsail convex luff curve in the supporting measurement diagram in Diagram 3/A. Is a concave luff curve allowed under the class rules?
A: No, a concave luff curve is not allowed under the DF65 and DF95 class rules. The class diagrams for DF65 (Diagram 3) and DF95 (Diagram A) specifically illustrate the mainsail luff measurement points B through F as positioned forward of a direct line from point A (Tack) to point G (Head). This arrangement mandates a convex luff curve, which is the only permissible curve shape according to our class rules.
Adhering to Section A.5, “Spirit of the Rules,” participants are expected to follow these specifications to ensure boats are raced on a level performance basis and costs are kept under control. The introduction of a concave luff curve would not only contradict the rule’s requirements but also take the design away from the majority of stock sails supplied with the boats and sails currently used across global fleets, potentially offering a performance difference and disrupting the uniformity intended by the class rules.
Effective Date: This interpretation is effective from 15th April 2024.
Issued by: DF Rules Committee
8th December 2022 – Rule Clarification for DF95 Rule H.2 Sail Construction
Question submitted by Dave Bell (GBR)
I would like to seek clarity on DF95 rule H.2.
Sails Construction
“The Jib and Mainsail of any given rig size shall be constructed from the same ply. “
It would appear that there is some confusion as to whether this simply means that;
1. A suit of sails should be made of the same base material of the same cloth weight (thickness) as in Mainsail and Jib are both 35um Mylar film.
2. A suit of sails must be cut from the exact same piece of cloth.
Logic would indicate that the former be true, allowing for replacement of individual sails should damage to an individual sail occur. Or use of the end of one roll, before starting the next.
However; this seems to be contradictory to the option of some who believe that ply is defined as “a sheet of sail material” or “SAME piece of cloth / material” and as such, a suit of sails would need to be only ever produced from the exact same piece of film / material.
I’ve had a look at the ERS, and cannot obviously see a clear definition. Please could you seek clarity?
Many thanks
Dave
Facts
In both the DF65 &95 rules, Rule H.2 states “Construction shall be a soft sail of a single ply. The Jib and Mainsail of any given rig size shall be constructed from the same ply.”
The Equipment Rules of Sailing has the following definition:
G.1.4 Sail Construction
(b) PLY
A sheet of sail material which may be made up of a number of layers.
Answer
If they are any visual, textural or colour differences between two sails in the same set, they cannot possibly be made from the same ‘Ply’ (sheet of material), therefore they do not conform to the class rules. This also covers different colours of the same brand of material e.g. Icarex.
Reasoning
The class rules are written in their simplest, clearest form to do away with almost all event measurement requirements. They are restricted class rules where, if it does not specifically say that you may, then you shall not. It is impossible to foresee every innovation which may be thought of in the future. Therefore when considering anything in connection with the boat or its sails or equipment (including choice of materials for any item) which is not clearly covered by the plans, specifications and/or rules, it must be assumed illegal unless prior approval has been obtained from the DFICA.
Whilst it may not be possible to be 100% certain by visual inspection that a jib & mainsail are manufactured from the same sheet of material (Ply), any visual or textural differences between the sails is enough evidence to indicate that they are not, and will be enough evidence to rule those sails out of class. Clearly any difference in colour, apart from permitted decoration, shows that they are not from the same sheet of material and is enough to have them ruled out of class.
If a sail becomes damaged and subsequently replaced, provided there is no apparent visual or textural difference to the other sail in that set, then is is reasonable to assume that it is made from the same Ply. If the damaged sail was manufactured by Joysway (The Licensed Builder) then it can be replaced by another Joysway sail of the same design despite any apparent minor visual or textural differences, provided you are not substituting an older woven sail for a newer Polyester film sail, or vice-versa.
Issued by the DFICA Rules Committee
8th December 2022
14th June 2021 – New DF65 and DF95 class rules issued. No current interpretations pending.
28th May 2021 – Clarification on Repairs to Hulls
So, it seems that there has been some confusion on the issue of repairing DF hulls that have broken and how that repair might affect the use of that repaired hull in another event in the future. Rather than have a million opinions on it and have everyone’s blood pressure rise unnecessarily we’ve had a chat to the DF Rules committee as it is currently and they have issued the following Rule interpretation for everyone to digest. The interpretation will also apply to the DF65 rules and more definition of what constitutes a legal repair will be detailed in upcoming rule revisions.
I don’t need to say any more than this, the rules committee statement below speaks for itself.
” The DF Rules committee have been made aware of a published interpretation by the American DF95 Executive of Rule A.7 ‘Repairs’ in the current DF95 Class Rules (Version 1.2). Their interpretation was never presented to the rules committee and does not reflect the original intention of the rule.
It is evident that in a minority of hulls there is an issue of cracking around the keel box, this is most likely due to inertia of the keel bulb during a collision or rough handling of the boat. In some instances it may be due to variations during the manufacturing process resulting in a thinner skin in this area. Rule A.7 allows for repairs to be made “provided they are not intended to enhance the original function or performance of the damaged items”. The Rules Committee and the rules author consider that a localised, internal repair around the base of the keel box is acceptable and will not enhance performance or change the original function of the hull. However, if the repair extends beyond this area or introduces additional structure, such as stiffening ribs or bulkheads, then it would clearly be a breach of rules A.5, A.6 & A.7.
Joysway have made several modifications to the moulding process to try and rectify this issue and are working with the designers on new ways to overcome this issue. In the next versions of the class rules, which will be published shortly, we will try to clarify the extent of what is considered a legitimate repair to the keel box area and there will be no time limit placed on the life of such a repair. In most class rules repairs are allowed, the DF classes should be no different provided they comply with any definitions in the class rules. Replacement hulls are available at a very reasonable cost but we feel that an owner should have the option to undertake a class legal repair and continue sailing their boat.
John Tushingham
DF Racing World Information Site 