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).