Clerk of course: The clerk of course (also called the "bullpen") assembles swimmers prior to each event, and is responsible for organizing ("seeding") swimmers into heats based on their times. Heats are generally seeded from slowest to fastest, where swimmers with no previous time for an event are assumed to be the slowest. The clerk of the course is also responsible for recording and reporting swimmers who have chosen to "scratch" (not swim) their events after they have signed up or qualified to a semifinal or final. The clerk is also responsible for enforcing rules of the swim meet if a swimmer chooses to not show up ("No show" - NS) to their events.
Timekeepers: Each timekeeper takes the time of the swimmers in the lane assigned to them. Unless a video backup system is used, it may be necessary to use the full complement of timekeepers even when automatic officiating equipment is used. A chief timekeeper assigns the seating positions for all timekeepers and the lanes for which they are responsible. In most competitions there will be one or more timekeepers per lane. In international competitions where full automatic timing and video placing equipment is in use timekeepers may not be required.
Inspectors of turns: One inspector of turns is assigned to one or more lanes at each end of the pool. Each inspector of turns ensures that swimmers comply with the relevant rules for turning, as well as the relevant rules for start and finish of the race. Inspectors of turns shall report any violation on disqualification reports detailing the event, lane number, and the infringement delivered to the chief inspector of turns who will immediately convey the report to the referee.
Judges of Stroke: Judges of stroke are located on each side of the pool. They follow the swimmers during their swim back and forth across the pool. They ensure that the rules related to the style of swimming designated for the event are being observed, and observe the turns and the finishes to assist the inspectors of turns.