The Portsmouth Yardstick is a handicap scheme which allows different types of boat to compete against each other (slower boats being given a higher handicap).
The higher the handicap the more time you have over other boats.
Examples:
| Class Name | PY Number | Class Name | PY Number |
| Albacore | 1038 | National 12 (HSC: 1600-2511) | 1145 |
| Cadet | 1435 | National 12 (HSC: 1-1599) | 1170 |
| Comet | 1205 | Ok | 1104 |
| Enterprise | 1116 | Optimist | 1655 |
| Europe | 1145 | Phantom | 999 |
| Graduate | 1129 | Phantom (HSC: – Plastic Hull) | 1025 |
| Gull | 1363 | Phantom (HSC: – Wooden Hull) | 1047 |
| Gull (Singlehander) | 1345 | Rooster 8.1 | 1051 |
| Laser | 1098 | RS Feva Xl | 1240 |
| Laser 4.7 | 1207 | RS Tera PR0 | 1364 |
| Laser Pico Race | 1330 | RS Tera Sport | 1432 |
| Laser Pico Race | 1335 | Solo | 1143 |
| Laser Radial | 1142 | Solution | 1087 |
| Mirror | 1390 | Supernova | 1075 |
| Mirror | 1380 | Topaz Uno Race | 1215 |
| National 12 (open meeting) | 1064 | Topaz Uno Race (2man) | 1248 |
| National 12 (HSC: 3519 +) | 1064 | Topaz Uno | 1251 |
| National 12 (HSC: 3415-3518)* | 1089 | Topaz Uno (2man) | 1263 |
| National 12 (HSC: 3272-3414) | 1104 | Topper | 1358 |
| National 12 (HSC: 3141-3271) | 1115 | Wanderer | 1190 |
| National 12 (HSC: 2512-3140) | 1130 | Wayfarer | 1102 |
More details on the Portsmouth Yardstick can be found here: RYA Portsmouth Yardstick.
