How sailing handicaps work.
Why the first boat home does not always win: elapsed and corrected time, time on time and time on distance, and the formulas of ORC, IRC, SRS and the Portsmouth Yardstick — with worked examples.
Line honours and corrected time
Line honours go to the first boat across the finishing line. Handicap racing lets different boats race each other fairly: each boat’s elapsed time (finish time minus start time) is converted into a corrected time with her rating, and the lowest corrected time wins.
Which system, and which number from a certificate, is set by the notice of race. The rating comes from the rating owner — a measurement certificate (ORC, IRC), a national list (SRS) or a published yardstick (PY). We do not publish rating lists; ask your club or the rating owner.
Time on time
Most systems multiply: corrected time = elapsed time × a time correction factor (TCF). A faster boat has a higher factor, so her elapsed time is “stretched” more.
| System | Formula | Bigger number means |
|---|---|---|
| ORC (time on time) | corrected = elapsed × ToT | faster boat |
| IRC | corrected = elapsed × TCC (to the nearest second) | faster boat |
| SRS | corrected = elapsed × SRS number | faster boat |
| Portsmouth Yardstick | corrected = elapsed × 1000 ÷ PN | slower boat |
Formulas as published by ORC, the IRC Rating Office, Svensk Segling and the RYA (sources below).
Worked example (IRC): boat A sails 1:30:00 with a TCC of 1.050 → 5 400 s × 1.050 = 5 670 s = 1:34:30. Boat B sails 1:32:00 with 1.010 → 5 520 s × 1.010 = 5 575 s = 1:32:55. B was second on the line and wins on corrected time by 1 minute 35.
The Portsmouth Yardstick
The RYA’s Portsmouth Yardstick gives each class a Portsmouth Number (PN): the higher the number, the slower the boat. Corrected time = elapsed × 1000 ÷ PN.
Worked example: a dinghy with PN 1100 sails 50:00 → 3 000 × 1000 ÷ 1100 = 2 727 s = 45:27. A faster dinghy with PN 1000 sails 46:00 → 46:00. The slower class wins by 33 seconds.
In average-lap racing boats sail different numbers of laps; the RYA formula scales them to the most laps sailed: corrected = elapsed × most laps × 1000 ÷ (PN × laps).
Time on distance
Time on distance gives each boat an allowance in seconds per nautical mile: corrected time = elapsed time − (allowance × course distance). It ignores the conditions, so it suits long races of known length. ORC certificates carry both time-on-time and time-on-distance values; performance-curve scoring, which also uses the wind strength, is a separate ORC method.
National systems
Many countries run their own handicap lists for club racing — Yardstick in Germany and the Netherlands, LYS in Finland, NOR rating in Norway, OSIRIS in France and others. Each owner publishes its own numbers and method. Our free calculator scores ORC, IRC, SRS, the Portsmouth Yardstick and any other time-on-time factor; it has no preset for those national systems yet, because we only add a system after checking its formula in an official source. If your notice of race says corrected = elapsed × your rating, use “other time-on-time factor”.
Ties, rounding and live estimates
- Rounding: IRC rounds corrected times to the nearest second; follow your system’s and your SIs’ rule.
- Ties in a race: boats with equal corrected times tie, and the points for the places involved are added and shared equally (Appendix A7); series ties are broken as Appendix A8 describes, unless the SIs say otherwise.
- Live corrected positions during a race are estimates: they project each boat’s current position to the finish. Only finish times give a result — that is why VesselSOS Racing marks them “proj.” and results stay provisional until the race committee publishes them.
A guide, not the rules. Your notice of race, sailing instructions, national prescriptions and race committee decide.
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