Many boats enter races or regattas and have dual scoring opportunities with divisions in both ORCi and IRC. This is seen in most major events in Australia. Whilst yachts can enter both divisions, the rating rules may have differences that competitors need to be aware of.

One difference under the two rating rules is crew weight. ORCi can either use a calculated crew weight or the owner can declare a crew weight. Under IRC rule 22.4.2 the maximum crew weight is limited by the ‘Crew Number’ on the certificate multiplied by 85kg. In the lead up to the Rolex Sydney Hobart Yacht Race at least one boat made the tough decision to change crew because under IRC they could not change the maximum weight so instead they had to look at who was going. In the 2022 Australian Yachting Championship held at the Lincoln Week Regatta also scored under IRC another boat had to do the same and change the crew list because the weight could not be changed, unlike under ORCi.

There are different limitations on what the crew can do with the boat's mast too. According to IRC rule 21.1.6(b), vertical movement of the mast at the foot or deck while racing is permitted as long as it is declared which enables the feature to be rated. However ORC rule 205 expressly prohibits any unnatural movement of the mast at the step or deck, and explicitly prohibits the use of mast jack pumps whilst racing.

Another difference is the setting of off-wind sails. IRC permits the use of headsails flown forward of the forestay, but ORCi has certain limitations.

ORC rule 208.2 requires that no flying headsails may be set forward of the forestay when a spinnaker is set. This rule was introduced at the same time as software changes to accommodate flying headsails. This was a policy position taken to prevent an arms race where a spinnaker and flying headsails tacked part way along the bowsprit were set simultaneously.

IRC takes a different approach where these are measured and rated accordingly. Consequently yachts have adopted headsail configurations in conjunction with a spinnaker that are quite permissible under the IRC Rule.

At the moment it is incumbent on crews to be aware of the differences in the rules for flying headsails, however, the complexities do make it difficult. Fortunately the ORC has made available an excellent document found here explaining the differences between the rules applicable on this issue.

Both organisations, ORC and IRC have recognised that the divergent approach is unhelpful to competitors and agreed to work on it. Their aim is to reach a point where neither rule imposes sail setting requirements not permitted by the other, even if each rating rule will treat sail setting configurations differently.

For information about ORCi click here.
For information about IRC click here.

By Glen Stanaway