Open Water Swimming (World Aquatics) Rules Explained

🚨 Cardinal Rule— Serious violation — may trigger retaliation or social exclusion

Don't deliberately grab, foul, or target a competitor's gear
— Physical contact is inevitable and legal in open water competition, but intentionally grabbing a rival's limbs, yanking goggles, or clutching a suit to impede them is considered a serious violation of competitive integrity — even when officials miss it or assess only a minor penalty.(High-profile incidents at Olympic and World Championship events have reinforced this norm)[1]
Signal officials if a competitor appears to be in medical distress
— Deeply rooted in swimming's safety culture: if you observe a fellow competitor showing signs of genuine distress — disorientation, non-movement, erratic behavior — you are expected to raise your arm and alert the nearest patrol boat or kayak, even at personal competitive cost.(Open water swimming carries real drowning risk; the sport's community treats this obligation as non-negotiable)[1]
Don't use the finish wall or timing pad to block a rival's touch
— Deliberately angling your body or outstretching an arm to physically prevent a competitor from reaching the timing pad at the finish is considered one of the sport's clearest ethical violations, regardless of whether a penalty is assessed.(Became more prominent as photo-finish and touch-pad technology made margin-of-touch decisive)

Section 1: Introduction

Open Water Swimming is the discipline of competitive long-distance swimming in rivers, lakes, seas, oceans, water channels, or any other body of open water, governed internationally by World Aquatics (renamed from FINA in January 2023). This rulebook reflects the World Aquatics Competition Regulations, in force as from February 2026 (effective 2026-02-18), Part Three: Open Water Swimming Rules, which supersedes the prior 2026-01-01 edition referenced by this site. Article 1.2 of Part Three defines Open Water Swimming as any swimming event that takes place in rivers, lakes, seas, oceans, water channels, or any other body of open water.

The Olympic Games program consists of a single event per sex: the 10 km race for men and women (Article 1.3 of Part Three). The World Aquatics Championships program is broader and now comprises the 10 km and 5 km individual races for men and women, the 3 km Knockout Sprint for men and women, and the Mixed Team Event — a 4 x 1500 m relay (Article 1.4 of Part Three). The 3 km Knockout Sprint is a new event format introduced under this edition (Article 7 of Part Three), and the team relay is now formally named the Mixed Team Event with each of the four Athletes completing a 1.5 km leg (Article 6.1.4 of Part Three) rather than the shorter 1.25 km legs used previously. The World Aquatics Junior Open Water Swimming Championships program runs age-banded 5 km, 7.5 km, and 10 km races, plus its own 3 km Knockout Sprint and relay events (Article 1.5 of Part Three).

Open water differs from pool swimming in several core ways codified in Part Three: navigation of the course is the Athlete's own responsibility (Article 4.1.2), limited contact and drafting are tolerated provided they are not unsporting (Article 4.2.4), and weather, tide, and water-quality conditions are directly regulated as part of the competition (Article 13 of Part Three).

Section 2: Equipment

Swimwear: at a water temperature of 18.0°C or above, an Athlete must wear one swimsuit in one or two pieces (not a wetsuit) that has been approved under Article 6 of Part One (Article 10.1 of Part Three).
Wetsuit: at a water temperature below 18.0°C, an Athlete must wear a wetsuit, with only one swimsuit permitted underneath (Article 10.2 of Part Three). If the water temperature is between 18.0°C and 20.0°C and the Chief Referee, on the advice of the Safety Officer and Medical Officer, determines conditions are hazardous, the Chief Referee may require all Athletes to compete in wetsuits (Article 10.3 of Part Three).
Cap: every Athlete must start the race wearing one or two approved caps in accordance with Articles 6.10 and 7.8.6 of Part One (Article 10.1–10.2 of Part Three); a swimmer wearing an unapproved cap, or two caps where either is unapproved, is disqualified (Appendix 7, items 6–7, of Part Three). Athletes competing as a team must wear a team cap of identical colour and style (Article 10.7 of Part Three, Article 7.8 of Part One).
Microchip transponders: each Athlete must start the race wearing two microchip transponders, one on each wrist; if a transponder is lost or becomes detached during the race, race officials will issue a replacement, and an Athlete who finishes without at least one transponder is disqualified (Articles 4.1.8–4.1.9 of Part Three). The transponders provide split and finish times to an accuracy of one tenth of a second when used with Automatic Officiating Equipment (Article 12.3.1 of Part Three).
Goggles, nose clip, ear plugs: permitted where approved under Article 6 of Part One (Article 10.1 of Part Three), but not mandatory.
Technology and wearables: devices such as drones, GPS trackers, or bio-medical sensors are not permitted unless approved in advance and listed on the World Aquatics current list of approved wearables; any technology or wearable used must be declared in the first call room, and failure to declare results in disqualification (Article 10.8 of Part Three).
No fins, paddles, webbed gloves, or other devices that aid speed, buoyancy, or endurance are permitted beyond what Article 10 of Part Three allows; Athletes must also have trimmed fingernails and toenails and must not wear jewellery, including watches (Articles 10.4–10.6, 2.19.1 of Part Three).
Feeding equipment: nutrition passed to an Athlete during the race must be in a biodegradable container, handed by hand or by a feeding pole no longer than five metres bearing no more than one national flag of maximum 30 cm x 20 cm (Article 4.4 of Part Three); Athletes may not carry gels or other packaged nutrition in their swimwear (Article 4.4.2 of Part Three).

Section 3: Playing Area

Course: the racecourse is laid out with a start/finish area, one or more turn buoys, and guidance buoys marking the swim line, as shown in the course diagram at Appendix 1 of Part Three. The course must be in water subject to only minor currents or tide and may be salt or fresh water (Article 13.1.2.1 / Appendix 1 notes of Part Three).
Turn buoys and guidance buoys: turn buoys marking alterations of the course are large inflatable markers roughly 3.00 m across and are a different colour to guidance buoys so Athletes can distinguish them (Article 12.1.4.1 of Part Three, Appendix 3 diagram); smaller guidance buoys of roughly 0.55 m line the course between turns to help Athletes hold the racing line (Appendix 1, Appendix 3 of Part Three).
Starting platform: at World Aquatics Events the starting platform length must be at least (number of Athletes x 0.60 m) plus five metres on each side, with Athlete start spaces 60 cm wide and numbered in ascending order (Articles 12.1.2.1–12.1.2.2 of Part Three).
Feeding platform: sized on the same formula using the number of feeders in place of Athletes (Article 12.1.5.1 of Part Three); floating feeding platforms or stationary feeding stations must be available at least every 2.5 km in races greater than 5 km (Article 14.3.6 of Part Three).
Finish: the finish apparatus is a vertical facing finish plate at least five metres wide, with its bottom edge no less than 500 mm and no greater than 700 mm above the waterline (Article 12.1.3.3 of Part Three); an Athlete finishes by touching the finish plate, or by crossing the finish line if no plate is used (Articles 5.3–5.4 of Part Three).
Course depth: the minimum water depth at any point on the course must be 1.40 metres (Article 12.2.2 of Part Three).
Water temperature: the water temperature must be a minimum of 16.0°C and a maximum of 31.0°C, checked at three points around the course at a depth of 40 cm two hours before the race by a commission of an appointed Referee, an LOC representative, and a team representative (Articles 12.2.3–12.2.3.3 of Part Three).
Water quality: venue suitability is determined against WHO-aligned Enterococci and E. coli thresholds — for seas, oceans, and other tidal waters, "excellent" water quality is Enterococci <100 cfu/100mL and E. coli <250 cfu/100mL, rising through "good," "fair," and "unacceptable" bands with correspondingly higher counts; inland waterways use higher thresholds at each band (Articles 13.1.3.3–13.1.3.4 of Part Three). Organisers must submit water quality analysis reports two months, seven days, and no more than 48 hours before the competition, plus a sample on the day of competition (Article 13.1.4.1 of Part Three).

Section 4: Players & Officials

Individual events: at the Olympic Games and World Aquatics Championships each Member Federation may enter a maximum of two Athletes per individual event (Article 9.1 of Part Three).
Mixed Team Event: each Member Federation may enter one team of four Athletes — two men and two women, all of the same sport nationality — with each Athlete completing the 1.5 km course once, in any order the team chooses provided the order is notified at the Technical/Team Leaders' Meeting (Articles 6.1.1–6.1.6, 9.2 of Part Three).
Age eligibility: an Athlete must be at least fourteen (14) years old as at 31 December in the year of the event to compete at the Olympic Games or World Aquatics Championships (Article 8.1 of Part Three); World Aquatics Junior Open Water Swimming Championships use 14–15, 16–17, and 18–19 age-group bands as at 31 December in the event year (Article 8.2 of Part Three).
Technical Officials: the organiser appoints, at minimum, one Chief Referee per event; at least three Referees, with one additional Referee for every twenty Athletes; a Chief Timekeeper plus two Timekeepers (unless Automatic Officiating Equipment and video recording of the finish are used, in which case one Timekeeper acts as Chief Timekeeper); a Chief Finish Judge and two Finish Judges; a Safety Officer; a Medical Officer; a Course Officer; a Clerk of the Course; a Turn Judge per course alteration; a Feeding Platform Judge per feeding platform; a Relay Judge; a Starter; an announcer; a Recorder; and, where a Video Assistant Referee system is used, a Video Review Judge (Articles 2.1.1–2.1.16 of Part Three).
Chief Referee authority: the Chief Referee has full control and authority over all Technical Officials, enforces all World Aquatics Rules, may stop a race if hazardous conditions jeopardise Athlete or official safety after consulting the Safety Officer and/or Medical Officer, and determines any disqualification arising from an infraction reported by another Technical Official (Articles 2.5.1–2.5.7 of Part Three).
Race Judges are appointed one per Athlete for events exceeding 10 km that are not run on a loop course, and are positioned on an Escort Craft to monitor their assigned Athlete throughout (Articles 2.1.9, 2.12.1–2.12.4 of Part Three).

Section 5: Rules of Play

The Start

At the Olympic Games and World Aquatics Events, Athletes start from a fixed starting platform, with positions assigned by random draw; at other competitions the organiser may instead choose an in-water start (Articles 3.1.1–3.1.2 of Part Three).
On the Starter's command "take your marks," Athletes must immediately take a starting position with at least one foot in contact with the front of the starting platform (or in line with the start line for an in-water start); failing to do so draws a yellow card (Article 3.3.4, 3.3.4.1 of Part Three).
The starting signal must be both audible and visual, using a white flag; if the Chief Referee considers the start unfair to any Athlete, the race may be restarted (Articles 3.3.5, 3.3.5.1 of Part Three).

During the Race

An Athlete must follow the course, round every turn buoy in the correct order and direction, not exceed the course boundaries, and complete the full course; failure to do so may result in disqualification from the event (Articles 4.1.2, 4.1.2.1 of Part Three).
An Athlete must not receive support from any fixed or floating object, or intentionally touch or be touched by anyone aboard an On-water Craft, except for medical reasons, and must not receive pacing from any non-competing person who has entered the water (Articles 4.1.4, 4.1.5 of Part Three).
The pacing or slip-streaming of an Athlete by any On-water Craft is not permitted; Race Judges will instruct an Athlete taking unfair advantage of a craft's wake to move clear (Articles 4.1.6–4.1.7 of Part Three).
Time limit: after the finish time of the first-placed Athlete, remaining Athletes have ten minutes per five kilometres (or part thereof) of the total course distance, up to a maximum of sixty minutes, to complete the course; an Athlete who exceeds the limit is recorded as over the time limit and removed from the water unless the Chief Referee permits completion (Articles 4.5.1–4.5.2 of Part Three).
Race emergency abandonment: a race of 10 km or less is restarted from the beginning at the earliest opportunity; a race longer than 10 km that is abandoned before two hours have elapsed is also restarted from the beginning, while abandonment after two hours produces a final ranking based on the results as reported by the Chief Referee (Articles 4.6.1–4.6.3 of Part Three).

Finish

An Athlete finishes by touching the finish plate (or crossing the finish line where no plate is used); an Athlete who does not touch the plate is disqualified (Articles 5.3–5.4 of Part Three).
Any violation within the limits of the finish funnel may result in disqualification, and where a Video Assistant Referee system is in use the Chief Referee enforces disqualification in conjunction with the Video Review Judge (Articles 5.5–5.6, 2.21.4 of Part Three).

Mixed Team Event

The first Athlete of each team starts together in accordance with the standard start procedure, and each team member must complete their 1.5 km leg consecutively before the next teammate enters the water (Articles 6.1.3–6.1.6 of Part Three).
Where a relay changeover platform is used, the incoming Athlete's feet must remain in contact with the platform until the outgoing Athlete touches it, then dive from their allocated start position; where no platform is used, both Athletes must be in the water and the contact between their hands or forearms must take place above the water (Articles 6.1.7.1–6.1.7.5.3 of Part Three).

3 km Knockout Sprint

The event runs over three rounds: Round One (1500 m), Round Two (1000 m, swum as one or two semi-final heats), and Round Three (500 m, a single final), each conducted under the same start, race, and finish rules as the standard race (Articles 7.2.1, 7.2.3, 7.3.1, 7.4.1, 7.5.1 of Part Three).
The top ten finishers of each Round One heat advance to Round Two (or the top twenty if only one heat is held), and the top ten finishers of Round Two advance to Round Three; Athletes are seeded into Round One heats by a "serpentine system" using World Aquatics Rankings (Articles 7.3.4–7.3.7, 7.4.6–7.4.7 of Part Three).
A yellow card issued during Round One or Round Two remains valid for all subsequent rounds in which the Athlete competes (Article 7.6.1 of Part Three).

Section 6: Scoring

Placings are determined by the Chief Referee from the Automatic Officiating Equipment where available; times and placings recorded by this equipment take precedence over Finish Judges' and Timekeepers' records (Articles 12.3.3.1–12.3.3.2 of Part Three).
If Automatic Officiating Equipment is not used or fails, official time is drawn from three Timekeepers' watches — using the two matching times if one differs, the intermediate time if all three differ, or the average of two working watches if only two function (Articles 12.4.1–12.4.1.1.4 of Part Three).
Where a Video Assistant Referee system is in place, a Video Review Judge reviews recorded images to support the Chief Referee's decisions on any reported infraction (Articles 12.5.1–12.5.2, 2.21.1–2.21.2 of Part Three).
In the 3 km Knockout Sprint, advancement between rounds functions as the scoring mechanism — top-ten (or top-twenty, single-heat) finishers progress round to round until a single Round Three final determines the event result (Articles 7.3.5–7.3.7, 7.4.6–7.4.7 of Part Three).
Individual race: lowest elapsed time wins. World Aquatics maintains sport-specific World Aquatics Rankings compiled from competition results, which are used, among other things, to seed the 3 km Knockout Sprint (Article 7.3.4 of Part Three; Article 2.197 of Part Nine).

Section 7: Violations & Penalties

Yellow card (first infraction): the Chief Referee or an appointed Referee raises a yellow flag and displays the Athlete's number as an official warning; the infraction is recorded and all Technical Officials are notified (Articles 4.2.2.3–4.2.2.4 of Part Three).
Red card (second infraction): a second rule breach in the same race draws a red flag and results in disqualification, enforced immediately or at the end of the race at the Chief Referee's discretion (Articles 4.2.2.5, 2.5.7 of Part Three).
Unsporting Conduct: defined as any intentional violent physical action; intentional pushing, pulling, or holding of another Athlete; intentionally pushing another Athlete against the finish-funnel buoys or markers; or any action impeding another Athlete from touching the finish plate — any of which results in immediate disqualification without requiring a prior yellow card (Articles 4.2.2.6, 4.2.4–4.2.4.4 of Part Three).
Missing the pre-race briefing without valid reason may draw disqualification or another penalty at the Chief Referee's discretion; arriving late without valid reason draws a yellow card (Articles 3.2.2, 3.2.2.1–3.2.2.2 of Part Three).
Swimwear and identification infractions (Appendix 7 of Part Three): wearing unapproved swimwear, wearing more than one swimsuit, not wearing a wetsuit when required, or starting without an approved cap each result in immediate disqualification; wearing jewellery or a watch is a Chief Referee decision between a yellow and red card.
Unauthorised aids: using or wearing any device or swimsuit that aids speed, buoyancy, or endurance, or using an undeclared or unapproved wearable, results in immediate disqualification (Articles 10.6, 10.8.2–10.8.3, Appendix 7 items 10–11 of Part Three).
Course violations: exceeding the outer course limits or failing to stay within the course boundaries results in disqualification (Articles 4.1.2, 4.1.2.1, Appendix 7 item 14 of Part Three).
Every Technical Official who observes an infraction must record it, notify the Chief Referee, and submit a signed Infraction Form after the race; Appendix 7 of Part Three provides a non-exhaustive quick-reference table of common infractions and their card classification (Articles 2.4, 4.2.3 of Part Three).

Section 8: Safety Considerations

Open water swimming carries risks not present in pool swimming — hypothermia, hyperthermia, exhaustion, marine hazards, and waterborne illness from contaminated water. Part Three requires the competition organiser to submit a site-specific Safety Plan to World Aquatics for approval four weeks before the competition, which a World Aquatics Safety Delegate reviews and may approve, modify, or reject; no competition may be sanctioned without an approved Safety Plan (Articles 14.2.1.1–14.2.1.6 of Part Three).

The Safety Plan must cover a Technical/Team Leaders' Meeting briefing on course hazards, tides, currents, marine life, and the evacuation plan (Article 14.3.1 of Part Three); continuous monitoring of every Athlete by at least one Safety Crew member or Referee at all times, with a stationary, CPR- and life-support-trained Safety Craft positioned at intervals of roughly every 400 metres along the course (Articles 14.3.3.1–14.3.3.3 of Part Three); an instant two-way safety communication system linking the Safety Delegate, Safety Officer, Safety Crew, Chief Medical Officer, and Chief Referee, with a dedicated emergency channel and backup (Articles 14.3.4.1–14.3.4.4 of Part Three); and a course evacuation plan for removing all Athletes, officials, and personnel from the water in an emergency (Article 14.3.11 of Part Three).

Medical requirements include a Chief Medical Officer experienced in endurance-event care, sufficient medical personnel trained in basic life support and CPR, onsite emergency and trauma equipment plus automated external defibrillators, and an ambulance available onsite or on call within five minutes (with a recommended backup within fifteen minutes); where travel time to the nearest hospital exceeds one hour, the Safety Plan must provide for helicopter transport (Articles 14.3.9.1–14.3.9.4 of Part Three).

Water temperature is checked at three points around the course, at a depth of 40 cm, two hours before the race and again at ten minutes before and every thirty minutes during the race; if the water measures below 16.0°C or above 31.0°C at any interval, the Chief Referee, on advice of the Safety and Medical Officers, may delay, postpone, or cancel the event, and may only restart a stopped race once the temperature is back within that 16.0–31.0°C range (Articles 12.2.3.3–12.2.3.7 of Part Three). Venue suitability is also gated on documented water quality — organisers must submit water-quality analysis reports at two months, seven days, and within 48 hours of the competition, and World Aquatics considers a venue in the "fair" or "poor" sanitary/bacterial category unsuitable for safe competition or training (Articles 13.1.4.1, 13.2.6.4 of Part Three).

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Overview

How to win

The game

🚨 Cardinal Rule— Serious violation — may trigger retaliation or social exclusion

Section 1: Introduction

Section 2: Equipment

Section 3: Playing Area

Section 4: Players & Officials

Section 5: Rules of Play

The Start

During the Race

Finish

Mixed Team Event

3 km Knockout Sprint

Section 6: Scoring

Section 7: Violations & Penalties

Section 8: Safety Considerations

Playing the ball

Fouls & penalties

Equipment

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