The sport of Ultimate has been known as a self-officiating sport but in situations where there is an important tournament or important game, observers may be called in by the Tournament Director and/or a team so as to keep order between the competing teams. Not every game at a tournament will have observers and not every tournament will have them.
Referees are less common in the Ultimate scene than observers.
Observers typically wear orange, collared shirts but they may wear any color shirt as long as the back says "Observer."
Often seen in tournaments of great importance like Sectionals, Regionals, and Nationals, all of which are Championship games. They can be seen facilitating youth, college, and club games.
Anyone can be an observer as long as they go through an official program and act professionally. There is an Observer Certification Program hosted by USA Ultimate that costs a small fee so that you are able to learn more about being an official observer.
They wear the black and white striped jersey that referees in other sports typically wear along with the black shorts.
Referees tend to facilitate in professional tournaments.
The main difference between the jobs of referees and observers is that referees can make calls like contact, foul, etc. When a referee makes a call, that is how the game is played; no discussion.
There are a lot fewer opportunities to become a referee compared to being an observer, but referees are most needed are professional games. If you understand most of the rules of Ultimate, you can find opportunities in the AUDL (American Ultimate Disc League).
All of the hand signals below are meant to be used to purely communicate information to everyone on and off the field about the situations that arise. These signals are not calls made by the observers themselves.
This is the only signal to indicate that the observer is making a ruling on a call, which cannot be revoked by the players.
Both hands on shoulders mean that the ruling made by the observer has been implemented. Observers can make a rule if players ask them to in the case of a dispute about a call. Once the players ask for the observers ruling, they must abide by the rules.
Blue cards indicate a Team Misconduct Foul like hard fouls, continuous violations, inappropriate language, etc.
Yellow cards indicate a Player Misconduct Foul like dangerous play, shoving, intentional fouls, swearing at an observer, etc.
Red cards indicate an ejection of a player.