Handicap racing
What Is an IRC Rating? Yacht Handicaps Explained
Publié · Dernière vérification octobre 2026
IRC is a handicap rule run by the Royal Ocean Racing Club and France's UNCL that lets different yachts race against each other fairly. Each boat gets a Time Correction Coefficient (TCC) from its measurements; multiply your elapsed time by your TCC and you get corrected time. The lowest corrected time wins.
How corrected time works
Corrected time = elapsed time × TCC. A faster boat has a higher TCC, so its time is stretched more.
| Bateau | Elapsed time | TCC | Corrected time |
|---|---|---|---|
| Fast 40-footer | 3h 00m (180 min) | 1.100 | 198.0 min |
| Cruiser-racer 34 | 3h 15m (195 min) | 1.000 | 195.0 min: wins |
The smaller boat finished 15 minutes behind but wins on corrected time.
What goes into a rating
- Hull length, beam and displacement
- Sail areas: mainsail, headsails and spinnakers
- Draft and keel type
- Crew weight limits and features such as a bowsprit or water ballast
The exact IRC formula is secret, which makes it hard to design a boat that exploits it. Owners apply for a certificate each year, and big events may require an endorsed, measured certificate.
IRC vs other systems
| System | Utilisé pour | Son fonctionnement |
|---|---|---|
| IRC | Keelboats, mostly UK, Europe and Australia | Secret formula, single TCC |
| ORC | Keelboats, strong in the Mediterranean and Baltic | Published velocity prediction, ratings vary with wind |
| Portsmouth Yardstick (PY) | Dinghies in the UK | Number based on real race results |
| PHRF | Keelboats in North America | Local committees assign seconds per mile |
How to get an IRC certificate
- Apply online to the IRC Rating Office (or your national rating authority).
- Provide your boat's details: hull data, sail measurements, crew weight and equipment.
- Choose a standard or endorsed certificate. Endorsed certificates need measurement checks and are required at many major events.
- Renew every year, and update the certificate whenever you change sails or equipment.
Why yacht handicaps are controversial
No handicap system is perfect. A rating can't predict how every boat performs in every wind strength, so heavy cruisers may do better in a breeze and light boats in light air. That's why some events run classes split by size or rating band, and why owners spend so much time optimising their certificates.
Getting into handicap racing
Most clubs run IRC or local handicap racing for cruiser-racers on weekend and evening series. You don't need an expensive boat: an older production cruiser with a fair rating can win on corrected time. Crewing for someone else is the easiest way in, and it's a great way to improve sail trim and weather helm control.