What does water resistance really mean?
Let me start off this post by saying: I'm new, I don't know much so I've come here for help.
Okay I'll tell what I know the 'meters' on your resistance rating isn't how deep you can go... It's the amount of pressure it can withstand. So 30 meters=3bar etc.
What I really don't understand is what you can do with these water resistance ratings.
Some people say that if you swim with anything less than 20bar your watch wil flood. And other say you can swim and snorkel with 5bar.
I'm just confused¯\(ツ)/¯
From what wr rating can I swim without worrying that I'll have to carry a water tank on my wrist.
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I'm a new teenage watch collector and dress watch and cat lover.
Netherlands
Member since
Last active: 3 weeks ago
17.27 cm
Screw down crown also helps as far as I know. Like 100m + screw down crown is a lot better than just 100m. I could be wrong but I think that’s correct😂
I read a good article on water resistance which of course I can no longer find to cite. However the gist of it was that water resistance ratings are probably true for the rated depth IF that’s the only force acting on them. But say you are swimming in 1 meter of water and your stroke arm with your watch on it is driving through the water… so the induced pressure from the force of your swimming action is representative of the static pressure of much more depth.
So someone does some math or observations to come up with a practical table like the handy one just posted which reflects the usual pressure forces acting on the watch.
I found this explanation helpful to make sense of why depth ratings, particularly at the smaller end of the scale, seemed to not relate well to the recommended activities.
So it’s not that watch makers put on bogus depth ratings, but that they don’t quite mean what we think.
I read a good article on water resistance which of course I can no longer find to cite. However the gist of it was that water resistance ratings are probably true for the rated depth IF that’s the only force acting on them. But say you are swimming in 1 meter of water and your stroke arm with your watch on it is driving through the water… so the induced pressure from the force of your swimming action is representative of the static pressure of much more depth.
So someone does some math or observations to come up with a practical table like the handy one just posted which reflects the usual pressure forces acting on the watch.
I found this explanation helpful to make sense of why depth ratings, particularly at the smaller end of the scale, seemed to not relate well to the recommended activities.
So it’s not that watch makers put on bogus depth ratings, but that they don’t quite mean what we think.
Thanks for sharing.
Now all of it makes a lot more sense.
10 ATM = 10 BAR = 100 meters -> safe for normal swimming
- anything above 10 ATM: safe to swim and maybe do more: surf, dive, …
- anything lower: would try to minimise water exposure
The water resistance rating is a number on the dial. It is there to make people feel good about their watch.
The quality of the machining, the assembly and the gaskets will determine water resistance. Gaskets will age, also. The daughter of a friend of mine turned her submariner into a salt water aquarium by not having the aging watch pressure tested. I have lost a watch rated for 50m to a hotel pool. I fell into a pond with a backpack, rifle, ammo, and all my gear. My quartz dress watch didn't mind.
Basically: Avoid chronos, love screw downs.
Basic rules for a carefree watch life aquatic ☺
I read a good article on water resistance which of course I can no longer find to cite. However the gist of it was that water resistance ratings are probably true for the rated depth IF that’s the only force acting on them. But say you are swimming in 1 meter of water and your stroke arm with your watch on it is driving through the water… so the induced pressure from the force of your swimming action is representative of the static pressure of much more depth.
So someone does some math or observations to come up with a practical table like the handy one just posted which reflects the usual pressure forces acting on the watch.
I found this explanation helpful to make sense of why depth ratings, particularly at the smaller end of the scale, seemed to not relate well to the recommended activities.
So it’s not that watch makers put on bogus depth ratings, but that they don’t quite mean what we think.
Dynamic pressure really doesn't add much at all compared to the static pressure of the water. Mark from Long Island Watch did the math, and 3m/s of movement equates to about 5cm of water depth.
He goes over this at around 19:10 here:
https://youtube.com/watch?v=-5NjrGPBEKs&feature=share8
That said I would avoid swimming with anything less than 100m due to thermal expansion and possible gasket degredation over time. And certainly not swim with 30m.
Dynamic pressure really doesn't add much at all compared to the static pressure of the water. Mark from Long Island Watch did the math, and 3m/s of movement equates to about 5cm of water depth.
He goes over this at around 19:10 here:
https://youtube.com/watch?v=-5NjrGPBEKs&feature=share8
That said I would avoid swimming with anything less than 100m due to thermal expansion and possible gasket degredation over time. And certainly not swim with 30m.
Interesting video! Thanks! Sounds like my point remains, that the watch, if in new condition and not a lemon, will withstand the rated static depth pressure. But the reason it’s not recommended to use to that depth are other peripheral factors (although apparently not movement through water!) So the recommended uses are based on the recommender’s risk tolerance and assumptions. So if you were somewhere that water temperature was close to air temperature and the immersion and resurfacing were done slowly to avoid thermal and pressure shock you’d probably get there and back?
Interesting video! Thanks! Sounds like my point remains, that the watch, if in new condition and not a lemon, will withstand the rated static depth pressure. But the reason it’s not recommended to use to that depth are other peripheral factors (although apparently not movement through water!) So the recommended uses are based on the recommender’s risk tolerance and assumptions. So if you were somewhere that water temperature was close to air temperature and the immersion and resurfacing were done slowly to avoid thermal and pressure shock you’d probably get there and back?
I'd assume so!
There's also the question of time. Given enough time, trace amounts of water will probably build up to something that could give water damage. So while 50m, or even 30m, of water resistance probably will be good for a surprise dip or two, I wouldn't take those for regular swimming even if the conditions are ideal (temperature, fresh water, somewhat static pressure).