How do swimmers know how far they have left in a long race?
I · Intermediate · The stroke · 2 of 7In the 400 m, 800 m and 1500 m freestyle an official at each end of every lane keeps count of the laps. Cards showing the laps still to go are displayed at the turning end. When a swimmer has two lengths and 5 m left, the official at the starting end sounds a bell or whistle.
How it works
- Which races: individual freestyle races of 400 m, 800 m and 1500 m.
- Who counts: each turn inspector, at the starting end and the turning end, records the laps completed by the swimmer in their lane.
- Lap cards: the swimmers are told the laps remaining "by the display of 'lap cards' that show odd numbers at the turning end of the pool".
- Where the cards go: at deck level or in the water. Electronic displays, including underwater ones, may be used.
- The warning: the inspector at the starting end gives a signal "when the Athlete in their lane has two laps plus five (5) metres to swim to finish".
- Repeated: the signal is repeated after the turn until the swimmer reaches the 5 m mark on the lane rope.
- The sound: "The warning signal may be by whistle or bell."
- In a 50 m pool: a 1500 m is 30 lengths, an 800 m is 16 and a 400 m is 8.
Tricky cases
Why do the cards show only odd numbers?
Because they are shown at the turning end. In a 50 m pool the swimmer reaches that end with an odd number of lengths left.
A swimmer miscounts and stops one length early. Does the result stand?
No. A swimmer must complete the course distance.
Is there a bell in the 200 m freestyle?
No. The lap count and the warning signal are for the 400 m, 800 m and 1500 m.
Why the rule exists
Thirty lengths is easy to lose count of when a swimmer is racing flat out with their face in the water. A miscount means stopping early or swimming on after the finish. The cards and the bell take the counting away from the swimmer.
Where it differs
| Where | What changes | Source |
|---|---|---|
| World Aquatics rules | As above | SW 2.8.6; SW 2.8.7 |
| 25 m pools | Twice as many lengths: 60 for a 1500 m | Arithmetic |
| Heats of the 800 m and 1500 m | At some championships only the fastest heat is swum in the finals session | SW 3.7.3 |
From the rule book
World Aquatics, Competition Regulations, Part Two: Swimming Rules (in force as from February 2026), Articles 2.8.6, 2.8.7 and 10.2.1. Checked 14 October 2026. Official document: World Aquatics Competition Regulations (PDF).