Are there rules about how a rowing boat is built?
Officials' detail · Boats, crews and the course · 1 of 3Boat design is largely free, but every class has a minimum boat weight: 14 kg for a single sculls and 96 kg for an eight. A boat must be at least 7.20 metres long, carry a white ball on its bow and have shoes that release at once. A boat found under weight after a race is placed last.
How it works
| Class | Minimum weight |
|---|---|
| Single sculls (1x) | 14 kg |
| Double sculls (2x) | 27 kg |
| Pair (2-) | 27 kg |
| Coxed pair (2+) | 32 kg |
| Four (4-) | 50 kg |
| Coxed four (4+) | 51 kg |
| Quadruple sculls (4x) | 52 kg |
| Eight (8+) | 96 kg |
- What is weighed: the boat with the fittings essential to its use, such as riggers, stretchers, shoes, slides and seats. Oars, the bow number and anything not fastened to the boat are not.
- Making the weight: extra weight carried to reach the minimum must be firmly fastened to the boat.
- Which boats are weighed: boats chosen by a random draw before each racing session, and any the president of the jury suspects. The crew is told as it leaves the water and takes the boat straight to the scales. Failing to do so brings exclusion.
- Under weight: the scales are tested and the boat weighed a second time. If it is still under, the crew is relegated to last place in that race and the result shows BUW. A second offence in a later round of the same event brings exclusion.
Other requirements:
- Length: at least 7.20 metres overall, so that every boat can be lined up on the start.
- Hull: a displacement mono-hull. Fins must be fixed and vertical. One rudder is allowed.
- The bow ball is a solid white ball of at least 4 cm covering the point of the bow.
- Shoes: foot stretchers or shoes must let rowers get clear of the boat without delay. Shoes that stay in the boat are tied down at the heel, and any fastening must open with a single quick pull on one strap.
- Flotation: a boat full of water with its crew seated must float with the top of the seat no more than 5 cm below the waterline.
- Oar blades: at least 5 mm thick for sweep oars and 3 mm for sculls, measured near the edge.
- The water: nothing may be used that changes the natural properties of the water or of the layer where hull meets water.
Tricky cases
A crew wins and its boat is then found under weight. Does it keep the win?
No. The sanction is relegation to last place in that race.
Can a crew add water bottles to bring the boat up to weight?
No. Loose items are taken out before weighing. Added weight counts only if it is firmly fastened to the boat or its essential fittings.
Is a wet boat weighed as it is?
Yes, in part. The normal wetted surface is accepted, but standing water must be removed before the weighing.
Can a team turn up with a new kind of boat?
It depends. Design is free in principle, but an innovation must be approved by the Executive Committee and be readily available to all rowers by 1 January to be used that year.
Why the rule exists
A lighter boat is a faster one, and without a minimum the richest teams would win an expensive race to build the lightest hull. The other requirements are about safety: a visible, blunt bow in a sport where nobody looks ahead, and shoes that let go when a boat turns over.
Where it differs
| Where | What changes | Source |
|---|---|---|
| World Rowing rules | As above | RR 29; RR 31; RR App R2; RR App R3 |
| Para rowing | Own minimum weights, such as 24 kg for the PR1 single sculls. The minimum length does not apply | RR App R3 (1); RR App R2 (1 b) |
| Eights | Must be built in at least two sections, none longer than 11.9 m | RR App R2 (1 a) |
| Fitted electronics | A standard allowance is subtracted for sensors left on the boat | RR App R3 (7) |
From the rule book
World Rowing Rules of Racing and Related Bye-Laws (Overall and Classic Rowing), Rules 29, 30 and 31 and Appendices R2 and R3. Last updated 1 July 2025. Checked 14 October 2026. Official document: World Rowing Rules of Racing (PDF).