Butterfly rules rules, for watching
Start with the rules you see all the time, then the ones that change results.
Checked 14 October 2026
Settling an argument? Search all 15 rules
- What are the butterfly races, and what are the rules?
- What makes a butterfly stroke legal?
- How far may a swimmer travel under water?
- How does a swimming race start?
- What happens when a swimmer goes before the signal?
- How must a butterfly swimmer touch the wall?
- What may a swimmer not do during a race?
- How are swimming races timed, and what if two swimmers record the same time?
- How does a swimmer get from the heats to the final?
- Who swims in which lane?
- What happens when two swimmers tie for the last place in the next round?
- Who disqualifies a swimmer, and can it be challenged?
- What may a swimmer wear in a race?
- What does a swim need to count as a world record?
- What are the measurements of a competition pool?
Where these rules come from
| Tag | Document |
|---|---|
| SW plus article number | World Aquatics, Competition Regulations, Part Two: Swimming Rules, in force as from February 2026. Read in full for this set: Articles 1 to 15 (programme, officials, seeding, the start, the four strokes, medley, the race, timing, world records, age groups, swimwear, facilities). Article 16 (medical and safety) was skimmed |
| "Part One" plus article number | World Aquatics, Competition Regulations, Part One: rules for all aquatic sports, in force as from 1 January 2025. Read for this set: Article 7 (swimwear) as far as the shape and material of swimsuits, and Article 13 (protests and appeals) |
| R | "Why the rule exists", or a point reasoned from the rule, not stated in it |
| C | Common usage or general knowledge, not a rule |
All checked on 14 October 2026. Both files are text PDFs with their article numbers in the text layer, so citations are to the printed article numbers.
The two parts are a year apart. The swimming rules are the February 2026 edition. The general part saved here is the January 2025 edition. The 2026 swimming rules refer to "Article 6 of Part One" for swimwear and "Article 12 of Part One" for appeals, where the 2025 edition has those in Articles 7 and 13. So Part One has been renumbered and may have changed. The pages that rely on it ("Disqualification and protests", "Swimwear and devices") say so.