A short history of the 10:20 protection standard
Dec 31, 2021RESEARCH DIGEST
What is the 10:20 protection standardTM?
The 10:20 protection standardTM, sometimes called a principle or system, is a lifeguard training aid to help lifeguards understand the importance of promptly identifying and reaching a pool user in danger. It is typically applied in commercial swimming pools and has less application to open water environments.
How does 10:20 work?
The 10:20 protection standardTM describes scanning your zone to identify and detect pool users in danger within 10 seconds and reaching that pool user within 20 seconds.
When was 10:20 first defined?
The 10:20 protection standardTM was popularized in the UK by following a study of 90 swimming pools involving c.500 proactive tests during three months in the summer of 2001 (Brener and Oostman, 2002). The standard existed in the USA and elsewhere since at least the 1970s.
The study aimed to assess the average time it took for lifeguards to identify a casualty. Lifeguards were asked to report when they saw a manikin on the pool bottom during an unprogrammed session involving a variable number of swimmers during each test. The manikin was placed in shallow and deep-water areas of the lifeguard zone during various indoor and outdoor operating conditions. The time between the submersion of the manikin and the detection of the manikin by the lifeguard was recorded. The study was never published in a peer-reviewed journal. The study included 511 tests and provided the following results (Brener and Oostman, 2002):
- 91% (465) of lifeguards had not detected the manikin after 10 seconds.
- 57% (291) of lifeguards had not detected the manikin after 30 seconds.
- 41% (209) of lifeguards had not detected the manikin after 1 minute.
- 23% (117) of lifeguards had not detected the manikin after 2 minutes.
- 13% (66) of lifeguards had not detected the manikin after 3 minutes.
The study's main outcome was to develop new techniques to improve the precision and sustainability of lifeguard scanning. The study did not evaluate the utility of the 10:20 protection standard and its ability to improve the performance of lifeguard scanning. It did show that 91% of lifeguards did not detect the manikin within a ten-second scan.
How is 10:20 used?
Pool operators, training organizations, and aquatic safety experts have tried to use 10:20 as a basis for related pool safety provisions, including:
- Limiting the length of a lifeguard's patrol route to ensure they can scan their responsible zone of the pool within ten seconds.
- Reducing the volume or surface area of a lifeguard's responsible zone so that a lifeguard can reach a pool user in danger within twenty seconds.
- Evaluating lifeguards' performance and ability to recognise an incident in the pool within ten seconds.
Is 10:20 achievable and realistic?
Studies in the intervening two decades have shed considerable light on the 10:20 Protection Standard™ and its limitations. It continues to be endorsed by Ellis & Associates in their 2020 lifeguard manual and is widely referenced by other lifeguard training bodies.
Hunsucker and Davison (2013) found in a US documentary analysis of pool inspection records that 79% of scans took less than 30 seconds, and only 42% were completed in under 15 seconds. The average scan time was 22 seconds.
Experienced lifeguards were found to use longer and more variable fixations than novice lifeguards (Vansteenkiste et al., 2021). Increased fixation duration is thought to increase the quality and quantity of data that informs decision-making and would be expected to lead to higher detection rates. Fixations were largely targeted at perceived higher-risk users within the visual field.
Observers were reported by Page et al. (2011) to miss changes to scenes they are observing frequently. Of the lifeguards that fixated on the correct location in the final 3.5 seconds in both conditions, 40% (biased) and 42% (non-biased) did not detect the person disappearing.
Additional points
Other points made across the literature include:
- In most published test results, the time taken to detect a drowning incident has been substantially longer than it would have taken to reach the casualty in the water.
- The time taken to identify the casualty has been shorter than the time to decide they are in danger. Line of sight to the casualty is often not enough.
- Better detection rates have been found in those who spend longer on each fixation, suggesting ten seconds may be insufficient to identify and detect a drowning incident.
- Better detection rates have been found in those who spend longer fixating on high-risk groups than fixating on equal time across the visual field.
- Failure to accurately detect a drowning incident (once identification has occurred) is more likely attributable to a lack of knowledge or experience than a failure to scan the pool effectively.
- Incidents vary in their degree of difficulty to detect and, consequently, the fixation duration required to reach an accurate detection.
- A failure to be the first to see the casualty may not be a fair reflection on lifeguard performance. Sometimes supervisors or other pool users may be the first to see the casualty in danger, affording little time for the lifeguard to make the first detection. Supervisors must retain some responsibility for identifying when the person under their care may be in danger and be supported by lifeguards once they are alerted.
Broadly speaking, once the decision to perform a rescue is made, the idea of reaching your casualty within 20 seconds or less has been widely adopted. In most cases, lifeguards have been shown to reach their casualty in substantially less than 20 seconds. Lifeguards typically outperform non-lifeguards regarding the speed of response to a drowning casualty.
References
Brenner, J., and Oostman, M. (2002). Lifeguards watch, but they don't always see! (World Waterpark Magazine, 14-16 May). 14–16.
Hunsucker, J. and Davison, S. (2013). Scan time goals with analysis of scan times from aquatic facilities. International Journal of Aquatic Research and Education. 7, 227-237. [A documentary analysis of two pools over 289 inspections involving 15,737 lifeguard observations over six years with one pool using a risk triage scanning strategy and the other using the 10:20 scanning strategy].
Page, J., Bates, V., Long, G., Dawes, P., and Tipton, M. (2011). Beach lifeguards: Visual search patterns, detection rates and the influence of experience. Ophthalmic and Physiological Optics. 31(3), 216 –224. [A recorded simulation study involving beach lifeguards and non-lifeguards].
United States Lifeguard Standards. (2011). An evidence-based review and report by the United States lifeguard standards coalition. Available at: http://www. lifeguardstandards.org/pdf/USLSC_FINAL_APPROVAL_1-31-11.pdf accessed 29th December 2021.
Vansteenkiste, P., Lenoir, M., Bourgois, J. (2021). Gaze behaviour of experienced and novice beach lifeguards. An exploratory in situ study. Applied Cognitive Psychology. 35, 251-257. [A study of sixteen Belgian beach lifeguards, nine with one-to-two years' experience and seven with over two years' experience, assessed using eye-tracking technology, a live beach scene between 12:30-18:00].
Citation: Jacklin, D. 2023. A short history of the 10:20 protection standard. Water Incident Research Hub, 27 December 2021; updated 12 May 2023.
