Semi-automatic timing

Semi-automatic timing, or semi-automatic officiating equipment, is a swim timing system that starts automatically from the starting device and is stopped by hand at the finish, by officials pressing buttons or by timers stopping watches that the start signal set running together. It sits between fully automatic timing, where a touchpad records the finish without human involvement, and manual timing, where a timer both starts and stops a watch. Because the start is electronic and only the finish is human, a semi-automatic time carries the timer’s reaction delay at one end but not the other, which is why the rulebooks rank it below automatic timing and above watches.

History and the move from watches¶

Semi-automatic timing is older than the touchpad. Omega’s Swim Eight-O-Matic, used at the 1956 Melbourne Olympic Games, is described by the company as the first semi-automatic swimming timer: its electronic counters were started by the starting pistol and stopped at the finish by officials holding electric pushbuttons.¹ Timing by hand at both ends was the alternative, so moving the start onto the starting device removed one of the two human reactions from every result.

The official report of the 1960 Rome Olympic Games describes the method in operation. Swimming used thirty timekeepers for the pool’s ten lanes, and each lane also carried an apparatus connected to the starter’s pistol, with the finishes recorded by the timekeepers pressing special buttons. Three times were taken per lane on the Omega Swim-O-Matic, each button worked by a timekeeper independent of the other two assigned to that lane, and the hand timekeeping service ran alongside the automatic system for finishes and for intermediate times.² An electronic start with three independent human finishes per lane, checked against watches, is the arrangement the rulebooks still describe.

The touchpad displaced the button from the primary role rather than retiring it, and it arrived earlier than the vendor accounts suggest. The official report of the 1964 Tokyo Games records a fully automatic finish-order apparatus, triggered from the starter’s pistol and reading the finish from a then-new touch board, which the Games made their official timer that year.³ The Munich 1972 report traces its own contact mats back to those Tokyo pads and marks one change over the intervening eight years: by 1972 the sensing was electronic, where Tokyo’s boards had still been pneumatic.⁴ World Aquatics, writing about its Omega partnership, instead dates the touch panel to the 1967 Pan American Games and the 1968 Mexico City Olympic Games.⁵ The organising-committee reports are the more authoritative source for what was installed at their own Games, and the Munich note about pneumatic boards suggests the later date belongs to the electronic pad rather than to touch boards as such. Once the swimmer’s own touch could stop the clock, buttons became the layer behind the pad, and the rulebooks were written around that arrangement: automatic equipment first, semi-automatic behind it, watches behind that.

How semi-automatic timing works¶

The start system sends its start pulse to the timing equipment at the same instant it sounds the tone and flashes the strobe, so every lane’s clock begins with the signal. What differs between the two forms of semi-automatic timing is where that clock runs. With buttons, the clock is in the timing console and each lane’s timer presses a button as the swimmer touches, stopping that lane’s clock. With a wireless stopwatch system, the clock is in each timer’s watch and the start signal starts every watch together, after which the timer stops the watch by hand.

Either way the finish is a human judgment, so a lane usually carries more than one, and the rules resolve the disagreement between them rather than trusting a single press. Buttons are designated A, B, and C, each read independently of the pad.⁶ A press records the timer’s reaction to the touch rather than the touch itself, which is why a semi-automatic time is treated as a check on a pad time and not as its equal.⁷

That reaction delay falls at one end of the race only, and the asymmetry is large enough that a console may correct for it. Colorado Time Systems’ System 5 software applies a 0.15 second correction whenever the two methods are mixed: a manual start has 0.15 seconds added to the recorded start time, and a manual finish, which is the semi-automatic case, has 0.15 seconds subtracted from the recorded time. CTS describes 0.15 seconds as the statistical median delay for manual start and finish timing and attributes the figure to two studies by J. Killpatrick, Timing Accuracies for Swimming (1975) and Timing and Judging Accuracies for Swimming (1976).⁸ Where both the start and the finish are taken by hand, which is manual timing, the manual states that no correction is needed, because the late start compensates for the late finish.⁸

CTS calls the two lane arrangements a touchpad finish and a button finish, and a facility can run either. On a button finish the buttons plug into the same lane harness connectors the pads would use, and with two buttons on a lane the console records the average of the two times.⁸

Governing-body requirements¶

Each governing body defines semi-automatic timing in its own rulebook, and the definitions match closely even where the procedures around them differ. World Aquatics defines the class by where the timer stops: for both automatic and semi-automatic equipment the timer is started manually by the starter, and under semi-automatic equipment either the touch panel stops it and the buttons are the backup, or, where there are no working touch panels, timekeepers pressing buttons stop the official timer themselves.⁹ The equipment must be activated by the starter, be accurate to a hundredth of a second, and not interfere with starts, turns, or the overflow system.⁹

How many buttons a lane needs has changed. Under the Facilities Rules 2021–2025, a major event could back its automatic equipment with semi-automatic equipment provided each lane carried three buttons under three different officials, one of whom might be that lane’s inspector of turns.¹⁰ The Competition Regulations in force from February 2026 carry the same provision with one button per lane rather than three.⁹ For records, a performance must be recorded by automatic equipment, or by semi-automatic equipment where the automatic system malfunctioned.⁹¹¹ Where a swimmer has no automatic time, the official time is the one recorded by semi-automatic equipment or by timekeepers.⁹¹¹

The two classes are started the same way and differ at the finish.

	Automatic officiating equipment	Semi-automatic officiating equipment
Started by	the starter	the starter
Finish recorded by	the swimmer’s touch on the panel	an official pressing a button
Buttons per lane as backup	not applicable	three (Facilities Rules 2021–2025), one (Competition Regulations from February 2026)

USA Swimming states the hierarchy directly, in the article numbered 102.23 since the 2023 rulebook and 102.24 before it, a renumbering that still catches out officials’ training material written against the older number.¹²¹³ Its rules rank the three in a preferred order of use. An automatic system takes its start from the starting device and its finish from the swimmer’s own touch on the pad. A semi-automatic system starts the same way, but the finish comes from timers pressing buttons as the swimmer arrives. A manual system leaves both ends to the timer, on individual lane watches.¹² A meet then designates its systems at three levels, and the rules fix what may serve at each.

Level	What may serve, in preferred order	When it is required
Primary	automatic; semi-automatic with three or two buttons per lane; manual with three watches per lane	always
Secondary	integrated overhead video at 100 images per second; semi-automatic with one, two, or three buttons; manual with one to three watches	unless the primary system is watches
Tertiary	at least one manual watch per lane	unless the primary is watches, or the secondary is integrated video or already includes a watch per lane

Each button or watch is operated by a separate timer, and secondary and tertiary times are recorded but not used except to corroborate or correct the primary result.¹² Where a lane produces more than one button or watch time, they resolve into a single time for that system.

Valid times available on a lane	Time for that timing system
Three, two of which agree	the agreeing time
Three, all disagreeing	the intermediate time
Two	the average, with thousandths dropped and not rounded
One	that time, unless it conflicts with other information

The NCAA rule matches this in substance, and adds that a result may not blend the secondary and tertiary tiers.¹⁴ A difference of approximately 0.30 second or more between the primary and backup times is one of the signs of a primary-system malfunction.¹²¹⁵ One timer may hold two devices only where they differ, a watch and a button rather than a pair of either.¹²

The NCAA classifies the same three tiers under its own numbering. On its definition a semiautomatic device may be started either from the starter’s signaling device or by hand, and is stopped by one or more officials on a button switch. Championship meets must field all three levels, which the NCAA glosses as primary equals automatic, secondary equals semiautomatic, tertiary equals manual watch.¹⁴ Its ranking does not place semi-automatic above manual across the board: two watches per lane outrank a single button.

Priority level	Equipment
1	Automatic
2	Two-button semiautomatic
3	Manual, two watches to a lane
4	One-button semiautomatic
5	Manual, a single watch to a lane
6	One or more alternate watches covering the field; at championship meets, one per lane at minimum

A time entered for an NCAA championship must be achieved on level one equipment. If the head judge confirms a malfunction there, level two is acceptable, and if level two also malfunctions, level three; no other level is accepted for championship qualification.¹⁴

The NFHS defines a semiautomatic timing device as one that starts manually or automatically and stops automatically or manually respectively, calibrated like every other device to a hundredth of a second.¹⁶ It names one automatic configuration and two backup classes.

Role	Equipment
Automatic timing	uniform electronic start with a touchpad finish
Backup, semi-automatic	uniform electronic start with timer-operated buttons at the finish
Backup, manual	watches started and stopped by timers

Even when automatic timing is used, the NFHS requires a manual timing device for each lane as backup, and its current guidance keeps semi-automatic times ahead of manual ones when a final time has to be established.¹⁶¹⁷ Because the thresholds and procedures differ between bodies, a meet follows the rules of its sanctioning organization.

Products¶

This section catalogs the semi-automatic timing equipment this wiki covers, in the two forms the rules recognize: wired buttons and wireless stopwatches.

Pushbuttons are the traditional form, a hand-held button per timer wired back to the timing console through a deck plate or cable harness. Colorado Time Systems (CTS) and Daktronics each make one, and Daktronics states that the two makers’ buttons are cross-compatible.¹⁸

Product	Manufacturer	Form	Status
Colorado Time Systems Pushbutton	Colorado Time Systems	Wired button (PB-6)	Current
Daktronics Pushbutton	Daktronics	Wired button	Supplied with deck-cabling systems

The Dolphin Wireless Stopwatch Timing System is the wireless form, in which each lane timer holds a stopwatch instead of a plugged-in button and the Dolphin Starter Unit starts every watch together from the start signal. USA Swimming has allowed wireless systems of this kind to serve as semi-automatic timing in sanctioned competition since April 13, 2023.¹⁹

Product	Manufacturer	Form	Status
Dolphin Wireless Stopwatch Timing System	Colorado Time Systems	Wireless stopwatches, synchronized start	Current

A CTS numeric scoreboard can take results from the Dolphin by radio, with no timing console in between, through the Dolphin Scoreboard Adapter, kit K-DSCB.

Each article covers its equipment in full, how a timer uses it, how it connects, and its care; this page is the shared overview they refer back to.

Other manufacturers sell semi-automatic equipment this wiki has not yet documented. International Sports Timing offers wired buttons as an alternative to touchpads for facilities on smaller budgets, with two buttons per lane in place of a pad.²⁰ ALGE-Timing sells its semi-automatic package in both a cabled form and a radio form, each covering eight lanes plus the start channel.²¹ Time Drops and Wylas Timing are newer entrants whose wireless buttons and phone-based watches take the start through an adapter cabled to an existing electronic start system.²²²³

See also¶

• Touchpads: the automatic equipment semi-automatic timing backs up
• Timers: the timing console that reads the buttons
• Start systems: the source of the start pulse that begins the timing
• Equipment: the equipment reference

References¶

Footnotes¶

1. Omega, 1956: Timing Down Under (Omega describes the Swim Eight-O-Matic as the first semi-automatic swimming timer). ↩

2. Rome Organising Committee, Official Report of the 1960 Olympic Games, v.1 (LA84 Foundation; thirty timekeepers, three buttons per lane). ↩

3. Tokyo Organising Committee, Official Report of the 1964 Olympic Games, v.1, p. 177 (LA84 Foundation; touch board adopted as the official timer). ↩

4. Munich Organising Committee, Official Report of the 1972 Olympic Games, v.1 (LA84 Foundation; contact mats first used in Tokyo 1964, electronic rather than pneumatic). ↩

5. World Aquatics, How Omega Keeps Advancing Timekeeping in Swimming (touch panels at the 1967 Pan American Games and the 1968 Olympic Games). ↩

6. Colorado Time Systems, Titanium Deckplate (TDP) (plug-in connections for touchpads and A/B/C backup pushbuttons). ↩

7. Wikipedia, Aquatic timing system (touchpads as primary timing with backup buttons and stopwatches). ↩

8. Colorado Time Systems, Swimming 5 Software User Guide (F506 Rev. 0698), pp. 2-2 to 2-3 (button finish) and 4-4 (timing corrections). ↩ ↩² ↩³

9. World Aquatics, Competition Regulations (Part Two: Swimming Rules), articles 11.1.7.2, 12, and 15.16 (semi-automatic officiating equipment; one button per lane at 15.16.5.2). ↩ ↩² ↩³ ↩⁴ ↩⁵

10. World Aquatics, Facilities Rules 2021–2025, FR 2.3.1 and FR 2.3.5 (finish recorded by buttons; three buttons per lane as backup). ↩

11. World Aquatics, Swimming Technical Rules 2023–2025, SW 12.8 and SW 13.3.2 (the earlier SW numbering for the same provisions). ↩ ↩²

12. USA Swimming, 2025 Rulebook, 102.23.2 (timing systems), 102.23.3 (designation), 102.23.4 (official time), 102.16.3 (lane timers). ↩ ↩² ↩³ ↩⁴ ↩⁵

13. The timing rules were 102.24 through the 2022 rulebook and 102.23 from the 2023 edition; the subsection text is unchanged. USA Swimming, 2022 Rulebook. ↩

14. NCAA, 2025-26 and 2026-27 Swimming and Diving Rules Book, rule 1-4-a (definition), 4-18-2 (priority levels), 4-14-4 (composite times). ↩ ↩² ↩³

15. SwimSwam, New USA Swimming Timing Malfunction Rules Take Effect (independent coverage of the primary/secondary/tertiary timing hierarchy). ↩

16. NFHS, Swimming and Diving Rules Book 2012-13 (Iowa HSAA copy), rules 1-2-2, 2-7-7, and 6-3-1. ↩ ↩²

17. NFHS, Swimming and Diving Finish Rules Best Practices (semi-automatic times take precedence at 6-4-1a; manual times at 6-4-1b). ↩

18. Daktronics, Are Daktronics and Colorado Timing System push buttons cross compatible? (KB DD2017009). ↩

19. Colorado Time Systems, Great News for Dolphin Users (USA Swimming semi-automatic use effective April 13, 2023). ↩

20. International Sports Timing, Timing systems (two buttons per lane in place of a touchpad for smaller budgets). ↩

21. ALGE-Swim USA, Solutions (cabled and radio semi-automatic packages, eight lanes plus the start channel). ↩

22. Time Drops, Wireless Swim Timing System (SA-1 start adapter relays the start from an existing electronic start system to wireless buttons). ↩

23. Wylas Timing, Wireless timing system (integrates with existing CTS and Swiss Timing starters). ↩