IRC is a rating rule to handicap different designs of keelboats allowing them to race together;
unlike a performance handicap a rating is not altered between races according to the individual boat’s performance, but is based on the physical measurements of the boat.
Each boat’s rating (her ‘handicap’) is calculated using measurements of the boat; her length, weight, draft, rig size, sail area, and specific characteristics and features. The resulting time corrector, the boat’s ‘TCC’, is her handicap. The higher the TCC figure, the faster the boat’s potential speed; IRC TCCs range from 0.750 to 1.9000, with the majority of cruiser/racers between 0.900 and 1.100. The numbers after the comma are thousandths, one thousandth is equivalent to 3.6 seconds per hour.
After a race, each boat’s elapsed time (the time she has taken to complete the course) is multiplied by her TCC to calculate her corrected time (her race time making allowance for the characteristics of the boat). The boat with the shortest corrected time is the winner of the race.

IRC is aimed at a very wide range of keelboats of all sizes and shapes including modern production cruisers and cruiser/racers through dedicated one-off race boats, older cruisers and racers to classic yachts and superyachts. IRC is continually developed to encompass new developments in both cruisers and racers while at the same time protecting the interests of the bulk of the fleet.

It is open to all types, sizes and ages of boats. IRC permits features such as asymmetric spinnakers, bowsprits, twin, triple, wing and drop keels, twin masts, gaff rigs, water ballast, canting keels, ‘code zero’ headsails, lateral daggerboards etc., and deals with these features as equitably as possible.

The methods and formulae used for the calculation of IRC TCCs are not published. This prevents designers taking advantage of the rule when designing new boats and very substantially increases the competitive lifetime of IRC rated boats. As a result, boats of all ages and types win races under IRC. Everything from classics through IOR designs to modern cruisers, cruiser/racers, and racers. The physics behind these formulas follow the major principles of architecture and performance applicable to sailboats from all era.

IRC is structured to be as simple as possible for both sailors and race administrators: there is no requirement for boats to be officially measured (unless required in individual countries). IRC accepts owner declaration of a boat’s measurements. All an owner needs to do is fill in the application form and send it to us. There is the option of an ‘Endorsed’ certificate, for which the data has been audited which may include official weighing and measurement. Measuring your boat will in the vast majority of cases, reduce the boat’s TCC.

IRC is used for a huge number of races and regattas all over the world, and it would be impossible to list them all! As a taster, apart from local club races IRC is used at (among many others) well known events such as: The Giraglia, the Transquadra, the Round the Island Race, Cowes Week, Rolex Fastnet Race, Volvo Cork Week, Les Voiles de St Tropez, the Rolex Big Boat Series, The Atlantic Rally for Cruisers, the Rolex Middle Sea Race, the Rolex Sydney Hobart Race, the Audi Hamilton Island Race Course, the Rolex China Sea Race, the Singapore Straits Regatta, the King’s Cup Phuket, the Newport Bermuda Race, the Spi Ouest France, the Drheam Cup, Armen Race, the Maxi Yacht Rolex Cup and the Mini Maxi, The Rolex World Championship, the Volvo Dun Laoghaire race, the Block Island Race Week and the RORC Brewer Dolphin Commodores’ Cup. (Event sponsors in August 2012).
Last year nearly 7000 boats in 30+ countries on all 6 continents held IRC certificates. Over 44000 boats have raced in IRC since its creation.

IRC and its national class associations
A rating rule defines a group of boats like in one-design (Class 40, Orma 60 or 470) and each boat is attached to a national class association. In France it is known as PROPIRC. As soon as you have paid the fee, you can complete your certificate.

IRC: Who issues the certificate?
Each country is attached to the UNCL or RORC Rule Authority. The class association or club in each country will tell you which authority to contact.

Find out more about the IRC Rating HERE