2024 IRC Rule Changes

Click to download the 2024 Rule Changes. (.pdf)

IRC RULE 8 – SECONDARY RATING CERTIFICATES

Reason for change: Owners and rule authorities request to have a second valid certificate for a separate configuration, for example inshore and offshore setup. The rule change allows a secondary certificate and specify those measurements and items that may be varied from the primary certificate. After successful trial in the southern hemisphere from August 2022 it is proposed to adopt this worldwide.

8.2.1 A boat may additionally hold a separate secondary valid certificate:

1. (a)  The secondary certificate will be clearly identified and shall only vary from the

   primary certificate in respect of, mainsail widths, E, P, headsail dimensions, flying headsail dimensions, single furling headsail allowance, the use of stored power, SPA, STL, SPL, spinnaker pole/bowsprit, whisker pole, number of spinnakers, number of flying headsails, aft rigging, use of moveable ballast, use of variable ballast, internal ballast;

2. (b)  The secondary certificate boat weight and corresponding overhangs shall only vary from the primary certificate for a change in internal ballast. This change in boat weight is only permitted when both the primary and secondary certificates are ENDORSED in accordance with IRC Rule 8.5.

3. (c)  Owners shall declare the primary or secondary certificate to the race organiser before the rating deadline.

Amend IRC Rule 22.4.2 as follows:

22.4.2 The crew weight shall not exceed 85kg multiplied by the Crew Number printed on the certificate.

2023 IRC RULE 15 and 21 – AFT RIGGING

Reason for change: In 2017 the IRC Rules and associated code moved away from separately defining Running Backstays and Backstays into a single term of Aft Rigging. After review this is a better term to use in the rules rather than define individual components of the aft rigging.

Amend IRC Rule 15 and 21.1.6 as follows:

15 MANUAL POWER

15.1 RRS 52, Manual Power, shall not apply. This Rule may be amended by Notice of Race.

15.2 (a)

The use of stored power for the hoisting of mainsails, or the reefing or furling of sail need not be declared.

1. (b)  Boats using stored power solely for the adjustment or operation of backstays aft

   rigging shall declare this to the Rating Authority.

2. (c)  Boats using stored power for the adjustment or operation of running rigging other

   than as noted in Rules 15.2(a) & (b) shall declare this to the Rating Authority.

3. (d)  Boats shall not use stored power for steering unless specified by the Notice of Race.

     

21.1.6 (a)

Effect:

Adjustment or detachment of forestay and/or shrouds including diagonal and jumper shrouds, or movement of the mast at the foot or the deck while racing is not permitted except:
(i) in the case of a boat without running backstays, checkstays or adjustable

backstay aft rigging when the forestay may be adjusted but not detached.

Use aft rigging rather than backstay etc. in the rule.

2022 IRC RATING CHANGES

This is not an exhaustive list of every development in the IRC rating formulation but covers the main changes and has been produced to help owners understand changes to IRC ratings. These are applied automatically in the rating software which is applied across the whole IRC fleet.

See https://ircrating.org/irc-rule/ for the full IRC Rule text and Appendix A Definitions, and details of Rule changes.

HEADSAILS

The rating formulation of headsails has been updated to address the rating imbalance of short luff/large roach headsails compared to equivalent area regular headsails.

FLYING HEADSAILS

The rating formulation for flying headsails has been updated such that flying headsail rating effect will be lower with specific consideration if there is a spinnaker declared for the boat.

LIGHT & POWERFUL (MODERN TYPE) BOATS

The rating formulation for relatively large, light and powerful boats such as TP 52s, Volvo 70s, Maxi 72s etc. has been updated with a rating increase. This also affects general light powerful boats to a lesser degree. For lighter powerful boats in the 30 to 40ft approximate range there is a small rating decrease.

BOW THRUSTERS

A tunnel bow thruster previously received a rating reduction by means of an adjustment to Hull Factor (HF). From 2022 this will be calculated within the software so HF will be the same with or without a bow thruster. Boats renewing an expired certificate with a tunnel bow thruster will see an increase in HF; however, there will be no change in the rating reduction due to the bowthruster. A retractable bow thruster previously received no HF adjustment. From 2022 there will be a small rating reduction and this will be calculated within the software. In both cases the bow thruster will be noted on the certificate.

WHISKER POLES

Rule 21.3.6 has been amended and IRC now only rates a whisker pole set to leeward:

21.3.6 Aboatshalldeclareusinganysparasawhiskerpolesettoleewardtosetaheadsailora flying headsail.

The rating effect is unchanged from 2021. Note: all boats have been reset to No Whisker Pole, so owner’s using a leeward whisker pole must declare it for their 2022 IRC rating, even if it was declared for the 2021 certificate.

2022

Flying Headsails

Recognising the evolution of sail types, IRC has introduced a new IRC definition of “Flying Headsail” with several rules in regards to the half width ratio to the foot length (greater than or equal to 62.5%), a maximum tack point position (STLFHmax), battens or stiffening of the sail are not permitted and several other rule requirements.

The Flying Headsail definition encompasses some ‘Code0’ sails that do not satisfy the Racing Rules of Sailing, Equipment Rules of Sailing or IRC definition of a spinnaker where the half width (SHW) shall be greater than or equal to 75% of the foot length (SFL).

Previously these sails rated as large headsails. Note that Code0s that are defined as a spinnaker are not impacted by this change.

See https://ircrating.org/irc-rule/ for the full rules and definitions relating to Flying Headsails.

A Flying Headsail is:

• Set Forward of the Forestay – either to the bow or a bowsprit
• The Half Width (FSHW) must be equal to or greater than 62.5% of foot length and less than 75% of foot length (FSFL);
• If the Half Width is less than 62.5% of foot length the sail must be rated as aheadsail. (This will increase the rating)headsail.
• If the Half Width is greater or equal to 75% of foot width the sail must be rated as aIf the Half Width is greater or equal to 75% of foot width the sail must be rated as spinnaker. (This will reduce the rating)
• No Battens
• typically these sails will be set on a furling device but this is not a mandatory requirement.
• The sail may not be set partially furled or partially reefed.

LIMITATIONS

The following limitations are requirements for a sail to be classed as a Flying Headsail. If it is not a Flying Headsail the sail must be rated as a Headsail or a Spinnaker depending on the FSHW/FSFL ratio.

• Half Width to Foot Ratio: = FSHW/FSFL
• Minimum FSHW = FSFL * 0.625
• Maximum FSHW = FSFL * 0.749
• STLFHmax – This is calculated for a specific sail using the formula: - STLFHmax = FSFL – (0.25 * J)

If the calculated STLFHmax is less than the value of J then the sail must be rated as a headsail.

This means that the minimum FSFL = 1.25 * J.

The sail must not be set further forward than the STLFHmax stated on the certificate. If STLFHmax is mid span of the bowsprit it may be that the bowsprit will not be strong enough at this point and the sail will need to be set further aft at a sufficiently strong point on the hull.

The STLFH cannot be declared by an owner and there is no rating benefit of declaring a STLFH that is shorter than STLFHmax.

Number of Flying Headsails

The number of Flying Headsails carried whilst racing is a rated value declared by the owner and shown on the certificate. A boat shall not have more than the rated number of Flying Headsails on board whilst racing.

A boat that has 2 Flying Headsails but is only rated for 1 Flying Headsail aboard may change between races/events subject to IRC Rule 21.1.5(d) and/or the Notice of Race.