5 ms·

All in all after watching several of their videos I feel like I do a good job of recognizing the drowning person, but I’m amazed at how quickly the lifeguards s

All in all after watching several of their videos I feel like I do a good job of recognizing the drowning person, but I’m amazed at how quickly the lifeguards spot it and dive into action. Even knowing that in this short clip there is absolutely someone drowning I still have doubt, but the lifeguard who doesn’t have that context is already half way to the person by the time I’m sure.

Hamuko 7y ago
How long of a shift do lifeguards even have? Because I wouldn't feel confident in being able to observe a bunch of people in a pool for hours for what are quite subtle clues.
- tnorthcutt 7y ago
  The lifeguards at my local (city) pool rotate very frequently; I’d say every 15 minutes or so. Their shift is longer of course, but they aren’t sitting observing for more than around 15 minutes at a time.
  - SilasX 7y ago
    Semi-OT: it came up in an earlier discussion that the 15 minute rule is common, and makes for better attention fatigue management than Uber has for SDC test drivers. https://news.ycombinator.com/item?id=19373662 https://news.ycombinator.com/item?id=19373662
- Waterluvian 7y ago
  Not sure this is indicative but at my local pool you can see them switching up between active duty and idling nearby in the hut about every 15 mins.
- dahfizz 7y ago
  I was a lifeguard at the YMCA, and we would never be on duty for more than 45 minutes at a time unless we were short staffed. You were constantly rotating and given short breaks or small tasks to keep sharp.
- hoorayimhelping 7y ago
  I was a lifeguard at Disney World (Disney lifeguards work the waterparks, all the resort pools, and the pool and the lake at the private cast member park, Mickey's Retreat) in the late 90s. I believe at the time it was 20 minutes on duty, 5-10 minutes rotating to the next station. There would always be a couple lifeguards rotating in this scheme and they'd able to assist if necessary. It was very boring, and keeping my mental acuity sharp towards the end of shifts was a problem. Take care swimming late in the day. Also, I don't ever swim in public pools anyone. We had to shut down the cast member pool one 4th of July because it was so dirty and so soiled, we couldn't see to the bottom of the deep end (6 feet / ~2m) and it presented a drowning hazard. The pool was closed for like 3 days after that while we waited for the water turbidity to go down.
  - zaroth 7y ago
    I think a pool closed for 3 days indicates gross mismanagement of chemical levels, not that contamination in public pools can’t be successfully managed. In theory a public pool under proper management should be cleaner than a private pool which almost certainly isn’t being professionally managed. Chlorine in pH balanced water with the right hardness is surprisingly effective. Pro tip, if you can smell “chlorine” it probably means the pool is dirty and doesn’t have enough chlorine left in the water. The smell is not chlorine in the water, it’s the result of the chlorine burning off as it oxidizes contaminants.
    - dugmartin 7y ago
      Yeah, the smell is from the combined chlorine (choloramines - https://en.wikipedia.org/wiki/Chloramines https://en.wikipedia.org/wiki/Chloramines). After having my own pool for 10+ years if I smell chrloramines in a public pool I won't go it in as it -- likely it is not managed well at all.
- qchris 7y ago
  I worked as a lifeguard at a lake's swimming area as a teenager, and I think it's a little less difficult than it sounds. It's not like staring out and hoping your peripherals catch something. Guards typically have discrete areas they cover, and within those boundaries you can check for a certain number of people and boundary crossings. By doing things like mentally running through the list/number of people in your area and noting the higher-risk ones, it's a little less mentally taxing than you might think. Combined with some overlap between guard stations and regular rotations between areas, coverage can be pretty good. The real difficulty comes in when you start adding numbers of people- the boundaries become less clear, the number of high-risk swimmers increase, and the total cycle time through everyone you're covering increases such that your margin of error between a situation presenting and your time to react starts decreasing. Anecdotally, I always found the behavior changes from a normal to tired swimmer to be one of the easier parts. Lack of forward motion, intense focus on the activity of swimming itself, falling behind from a group. Again, it's more difficult the more crowded an area becomes.
0xBA5ED 7y ago
Of course the lifeguard has extra context by just being in the same space with these people beforehand. They're probably already watching certain people more closely before the video starts while you and I enter the space cold (and through a fixed window).
- Drakar1903 7y ago
  I wonder how people would feel about machine-learning enhanced lifeguard system. Machines are sharp all the time.
  - kqr 7y ago
    At least machines are consistently dull.
  - michaelt 7y ago
    This is such a good idea there are several already on the market: https://youtu.be/Gka9TFwqoVs?t=60 https://youtu.be/Gka9TFwqoVs?t=60 https://youtu.be/FTtHOZfV_qA?t=47 https://youtu.be/FTtHOZfV_qA?t=47 https://www.straitstimes.com/singapore/drowning-detection-system-to-be-set-up-at-28-public-pools https://www.straitstimes.com/singapore/drowning-detection-sy... https://swimeye.com/ https://swimeye.com/
- OkayPhysicist 7y ago
  Almost certainly. Of the saves I made over the years, the only one where I wasn't already giving the victim extra attention for 5-10 minutes was a seizure.
JshWright 7y ago
The guards actually have a lot more context. They have been watching the people in the pool and have mentally sorted them by how much attention they need. They have also been staring at the same pool for hours and their brain is ignoring all the visual noise that is distracting you. They also have the benefit of stereo vision and sound.
- Zenst 7y ago
  You're spot on, the visual risk assessment aspect plays a big part as does the whole environment filtering aspect. Also helps that in this instance, most have rubber rings and if you see an empty rubber ring, that in itself would trigger concerns and focus.
- smabie 7y ago
  They’re also twirling their whistle which helps a lot, I’m sure.
  - SilasX 7y ago
    When I took the Lifesaving merit badge, they said that lifeguards have to carry the whistle because it will get in the way if they wear it around their neck when trying to make a rescue.
    - inetknght 7y ago
      Lifeguards in my area have the whistle on a wristband for that exact reason plus so they don't accidentally drop it while fumbling around with it when not paying attention
    - AstralStorm 7y ago
      It's more that a drowning person will grab anything, and if that thing is on your neck it will make the rescue more problematic than it already is. (Which is also why the lifeguards here are told to approach from the side, less likely to be grabbed on the head that way.)
- 7y ago
b0rsuk 7y ago
In case of lifeguards it's probably best to react even if you have doubts. Human life is at stake, better safe than sorry.
stanski 7y ago
To be fair, I think the lifeguards also have a better view than the low camera in the corner of the pool.
kelnos 7y ago
In this video I recognized pretty quickly who the drowning kid was, well before the lifeguard jumped in, but upon further reflection: 1) I was already primed to find someone drowning; I knew based on the video title that there was someone in danger. For a lifeguard, it's probably common that they'll go through entire shifts without having to jump in. 2) Even after identifying the right kid, I had doubt: I wasn't 100% sure until the lifeguard jumped in and confirmed my choice.

Hamuko 7y ago

How long of a shift do lifeguards even have? Because I wouldn't feel confident in being able to observe a bunch of people in a pool for hours for what are quite subtle clues.

tnorthcutt 7y ago
The lifeguards at my local (city) pool rotate very frequently; I’d say every 15 minutes or so. Their shift is longer of course, but they aren’t sitting observing for more than around 15 minutes at a time.
- SilasX 7y ago
  Semi-OT: it came up in an earlier discussion that the 15 minute rule is common, and makes for better attention fatigue management than Uber has for SDC test drivers. https://news.ycombinator.com/item?id=19373662 https://news.ycombinator.com/item?id=19373662
Waterluvian 7y ago
Not sure this is indicative but at my local pool you can see them switching up between active duty and idling nearby in the hut about every 15 mins.
dahfizz 7y ago
I was a lifeguard at the YMCA, and we would never be on duty for more than 45 minutes at a time unless we were short staffed. You were constantly rotating and given short breaks or small tasks to keep sharp.
hoorayimhelping 7y ago
I was a lifeguard at Disney World (Disney lifeguards work the waterparks, all the resort pools, and the pool and the lake at the private cast member park, Mickey's Retreat) in the late 90s. I believe at the time it was 20 minutes on duty, 5-10 minutes rotating to the next station. There would always be a couple lifeguards rotating in this scheme and they'd able to assist if necessary. It was very boring, and keeping my mental acuity sharp towards the end of shifts was a problem. Take care swimming late in the day. Also, I don't ever swim in public pools anyone. We had to shut down the cast member pool one 4th of July because it was so dirty and so soiled, we couldn't see to the bottom of the deep end (6 feet / ~2m) and it presented a drowning hazard. The pool was closed for like 3 days after that while we waited for the water turbidity to go down.
- zaroth 7y ago
  I think a pool closed for 3 days indicates gross mismanagement of chemical levels, not that contamination in public pools can’t be successfully managed. In theory a public pool under proper management should be cleaner than a private pool which almost certainly isn’t being professionally managed. Chlorine in pH balanced water with the right hardness is surprisingly effective. Pro tip, if you can smell “chlorine” it probably means the pool is dirty and doesn’t have enough chlorine left in the water. The smell is not chlorine in the water, it’s the result of the chlorine burning off as it oxidizes contaminants.
  - dugmartin 7y ago
    Yeah, the smell is from the combined chlorine (choloramines - https://en.wikipedia.org/wiki/Chloramines https://en.wikipedia.org/wiki/Chloramines). After having my own pool for 10+ years if I smell chrloramines in a public pool I won't go it in as it -- likely it is not managed well at all.
qchris 7y ago
I worked as a lifeguard at a lake's swimming area as a teenager, and I think it's a little less difficult than it sounds. It's not like staring out and hoping your peripherals catch something. Guards typically have discrete areas they cover, and within those boundaries you can check for a certain number of people and boundary crossings. By doing things like mentally running through the list/number of people in your area and noting the higher-risk ones, it's a little less mentally taxing than you might think. Combined with some overlap between guard stations and regular rotations between areas, coverage can be pretty good. The real difficulty comes in when you start adding numbers of people- the boundaries become less clear, the number of high-risk swimmers increase, and the total cycle time through everyone you're covering increases such that your margin of error between a situation presenting and your time to react starts decreasing. Anecdotally, I always found the behavior changes from a normal to tired swimmer to be one of the easier parts. Lack of forward motion, intense focus on the activity of swimming itself, falling behind from a group. Again, it's more difficult the more crowded an area becomes.

0xBA5ED 7y ago

Of course the lifeguard has extra context by just being in the same space with these people beforehand. They're probably already watching certain people more closely before the video starts while you and I enter the space cold (and through a fixed window).

Drakar1903 7y ago
I wonder how people would feel about machine-learning enhanced lifeguard system. Machines are sharp all the time.
- kqr 7y ago
  At least machines are consistently dull.
- michaelt 7y ago
  This is such a good idea there are several already on the market: https://youtu.be/Gka9TFwqoVs?t=60 https://youtu.be/Gka9TFwqoVs?t=60 https://youtu.be/FTtHOZfV_qA?t=47 https://youtu.be/FTtHOZfV_qA?t=47 https://www.straitstimes.com/singapore/drowning-detection-system-to-be-set-up-at-28-public-pools https://www.straitstimes.com/singapore/drowning-detection-sy... https://swimeye.com/ https://swimeye.com/
OkayPhysicist 7y ago
Almost certainly. Of the saves I made over the years, the only one where I wasn't already giving the victim extra attention for 5-10 minutes was a seizure.

JshWright 7y ago

The guards actually have a lot more context. They have been watching the people in the pool and have mentally sorted them by how much attention they need. They have also been staring at the same pool for hours and their brain is ignoring all the visual noise that is distracting you. They also have the benefit of stereo vision and sound.

Zenst 7y ago
You're spot on, the visual risk assessment aspect plays a big part as does the whole environment filtering aspect. Also helps that in this instance, most have rubber rings and if you see an empty rubber ring, that in itself would trigger concerns and focus.
smabie 7y ago
They’re also twirling their whistle which helps a lot, I’m sure.
- SilasX 7y ago
  When I took the Lifesaving merit badge, they said that lifeguards have to carry the whistle because it will get in the way if they wear it around their neck when trying to make a rescue.
  - inetknght 7y ago
    Lifeguards in my area have the whistle on a wristband for that exact reason plus so they don't accidentally drop it while fumbling around with it when not paying attention
  - AstralStorm 7y ago
    It's more that a drowning person will grab anything, and if that thing is on your neck it will make the rescue more problematic than it already is. (Which is also why the lifeguards here are told to approach from the side, less likely to be grabbed on the head that way.)
7y ago

b0rsuk 7y ago

In case of lifeguards it's probably best to react even if you have doubts. Human life is at stake, better safe than sorry.

stanski 7y ago

To be fair, I think the lifeguards also have a better view than the low camera in the corner of the pool.

kelnos 7y ago

In this video I recognized pretty quickly who the drowning kid was, well before the lifeguard jumped in, but upon further reflection: 1) I was already primed to find someone drowning; I knew based on the video title that there was someone in danger. For a lifeguard, it's probably common that they'll go through entire shifts without having to jump in. 2) Even after identifying the right kid, I had doubt: I wasn't 100% sure until the lifeguard jumped in and confirmed my choice.