Relay take-off platforms

A relay take-off platform is a sensing surface mounted on top of a starting block that records the instant the outgoing swimmer’s feet leave the block during a relay exchange. The timing console compares that departure time with the moment the incoming swimmer touches the touchpad in the same lane, producing an exchange differential that shows whether the outgoing swimmer left early.¹² The names are vendor-specific: Colorado Time Systems sells the RJP (relay judging platform) and Daktronics sells the RTOP (relay take-off platform), while the World Aquatics rules refer to the function as relay take-off judging and the NCAA rulebook uses relay judging platforms.¹²³⁴

The same departure signal also measures start reaction time, the interval between the start signal and the swimmer leaving the block. Consoles that support it can post the reaction time to the scoreboard, and coaches use the readout as a training tool.¹⁵

How automatic relay judging works¶

In a relay, a swimmer’s feet must still be in contact with the starting platform when the preceding teammate touches the wall; a team whose swimmer leaves early is disqualified.⁶⁷ An automatic relay judging installation pairs the lane’s touchpad with a platform on the block. The console subtracts the incoming swimmer’s finish time from the outgoing swimmer’s take-off time: a negative differential means the swimmer left before the touch, and a zero or positive differential means the exchange was legal.⁴⁸ Because the exchange is judged against the pad, USA Swimming requires each relay swimmer to finish on the touchpad when automatic relay take-off judging is in use.⁷

Manufacturers detect the departure in different ways. Colorado Time Systems platforms register the mechanical unloading of the platform’s top and leading edge, and the company states they are engineered to distinguish weight shifts from an actual departure.⁵ Daktronics platforms instead sense the swimmer’s body capacitively, an approach the company patented in the 2000s; Daktronics states the reading does not depend on the swimmer’s weight or the style of start.⁹²

No platform resolves the moment of departure exactly, so each manufacturer defines its own zero point and tolerance. The World Aquatics facilities rules state that for the differential in relay take-offs “the manufacturer of the device shall be consulted”.³ Colorado Time Systems adds a fixed 0.01 second to every exchange time its timers calculate, in favor of a safe take-off (see the Colorado Time Systems RJP article),⁵ the NCAA rule defines its decision window relative to “the manufacturer’s starting point”,⁴ and SwimSwam has reported that Omega, whose equipment times major international meets, recommends a tolerance of minus 0.03 seconds, within which an exchange is not called early.¹⁰⁸

Governing-body requirements¶

Under the World Aquatics facilities rules, relay take-off judging to 1/100 of a second is one of the essential accessories of automatic officiating equipment, and where overhead video cameras are installed they may be reviewed as a supplement to the automatic judgment.³ Take-offs judged by the automatic equipment take precedence over the officials at the blocks.⁶ The referee still appoints officials to determine whether each starting swimmer is in contact with the platform at the touch, and the control room supervisor checks the relay exchange printout, reports early take-offs to the referee, and may review video timing to confirm one.⁶

USA Swimming rules follow the same pattern. When automatic relay exchange judging equipment is in use, the system printout provides the information to judge relay exchanges; integrated backup timing cameras may be reviewed by the referee to confirm the system’s results, and when no cameras are available the referee determines the confirmation process.⁷ Without equipment, relay take-offs are judged by officials, and when dual take-off judging is used a relay is disqualified only if the lane judge and the side judge independently report the same infraction in writing.⁷

NCAA rules give the equipment the most authority. When electronic relay takeoff equipment records an exchange differential between minus 0.09 and plus 0.09 seconds from the manufacturer’s starting point, the equipment’s determination is official and the decisions of human judges are not considered: minus 0.09 through minus 0.01 indicates a violation, and 0.00 through plus 0.09 indicates a legitimate exchange. Outside that range, a disqualification requires dual confirmation by the equipment and either a judge or approved video.⁴ The NCAA rulebook also requires that track-start blocks used in meets requiring relay judging platforms accommodate the platforms.⁴

At the high school level, procedures vary by state association. The Texas UIL protocols, for example, assign at least two take-off judges, require judge confirmation of any negative reading on non-Omega equipment (below minus 0.03 on Omega equipment), and do not charge a violation on a reading of 0.00 or better unless an official observed contact with the block.⁸

Reliability and disputes¶

Automatic relay judging has produced disputed disqualifications. A Stanford relay was disqualified by the equipment at the 2008 NCAA Division I Women’s Championships, and in 2011 the publisher of Swimming World, Brent Rutemiller, called for the use of electronic relay take-off platforms to be suspended until human judgment was restored to the process, arguing that meets without backup cameras let the printout alone decide borderline readings.¹¹ Rules have since leaned on review: the NCAA requires video review of relay takeoff disqualifications where review is in place, and USA Swimming allows the referee to review integrated backup cameras.⁴⁷

Products¶

Two United States timing manufacturers sell relay judging platforms as lane accessories to their timing systems, and Omega (Swiss Timing) equipment provides the same function at the international meets it times.¹²¹⁰

Product	Manufacturer	Sensing	Status
Colorado Time Systems RJP	Colorado Time Systems	Mechanical, top and leading edge	Current
Daktronics RTOP	Daktronics	Capacitive	Current
Omega relay take-off platform	Swiss Timing	Integrated with Omega starting blocks	Current

The Colorado Time Systems RJP article covers the RJP and RJPLD lines and the Daktronics RTOP article covers the RTOP models in full; this page holds the shared background on how the platforms are judged and ruled on.

See also¶

• Touchpads: the finish input the exchange is judged against
• Pushbuttons: the other lane accessory read alongside the pad
• Timers: the timing console that computes the exchange differential
• Start systems: the source of the start impulse used for reaction times
• Equipment: the equipment reference

References¶

Footnotes¶

1. Colorado Time Systems, Relay Judging Platforms for Competition (exchange judging and start reaction time to 1/100 second). ↩ ↩² ↩³

2. Daktronics, Relay Take-Off Platform (senses human contact rather than force; not dependent on the athlete’s weight). ↩ ↩² ↩³

3. World Aquatics, Facilities Rules 2021–2025, FR 2.3.6.3 (relay take-off judging to 1/100 second; overhead video as a supplement; the manufacturer consulted for the differential). ↩ ↩² ↩³

4. NCAA, Swimming and Diving Rules Book (electronic relay takeoff equipment differential windows; blocks must accommodate relay judging platforms; video review). ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶

5. Colorado Time Systems, RJPLD User Guide (F968) (sensing, training use, and the fixed 0.01 second exchange adjustment). ↩ ↩² ↩³

6. World Aquatics, Swimming Technical Rules 2023–2025, SW 10.13 (early take-off disqualification), SW 2.1.9 and SW 2.6.8 (officials judge contact), SW 2.2.3 and SW 2.2.4 (relay exchange printout and video), SW 13.1 (precedence of automatic equipment). ↩ ↩² ↩³

7. USA Swimming, 2025 Rules and Regulations, 101.7.4 (pad touch required under automatic relay take-off judging; early take-off disqualification) and 102.13.6 (take-off judges, dual confirmation, and the system printout). ↩ ↩² ↩³ ↩⁴ ↩⁵

8. University Interscholastic League, Protocols for Electronic Relay Judging Equipment (judge assignments and confirmation thresholds by equipment type). ↩ ↩² ↩³

9. Google Patents, US 7,403,135: Capacitive relay takeoff swimming platform sensor system (Daktronics; capacitive departure sensing; priority 2003, granted 2008). ↩

10. SwimSwam, Why Was Australia’s -0.03 Relay Start Not A DQ? A Rules Deep Dive (the manufacturer-consulted differential and Omega’s reported minus 0.03 second tolerance). ↩ ↩²

11. Swimming World, Suspend the Use of Electronic Relay Take-Off Platforms (2011 editorial; the 2008 Stanford disqualification). ↩

12. Daktronics, RTOP and starting block compatibility (Omega relay take-off platforms and starting blocks alongside Daktronics RTOPs). ↩