I don’t take WR too seriously unless it’s on a diver’s watch that’s specifically rated for diving.
For example: the old SKX (007, 009, 011, 013) was an ISO rated diver’s watch. That watch stated a 200m water resistance (right on the dial), and, under ISO guidelines, it had to perform at a minimum 125% of that rating to be certified as a diver’s watch.
The new 5KX, which looks like the old SKX, states nothing on the dial, but claims a 100m water resistance in the manual. This might be true, but I would not expect it to perform up to this rating because it is not a certified diver’s watch. That said, i’s probably safe to swim with in normal swimming pool conditions.
The short, follow the manufacturer’s guidelines and get a real diver if you’re diving.
I’ve swam with my SNK809 Seiko 5 (30m water resistance)
Alternatively, I’ve heard internet stories of water/moisture damage from brand new Hamilton Khaki’s (50m)
Water resistance on mechanical watches is highly variable. The terminology used is not standardized - they aren’t using IP ratings for example. “100m resistance” may mean different things between different companies.
Your best bet is always going to be to follow manufacturers recommendations.
I do most of my scuba dives with a “water resist” Casio F91, and I’ve taken most of my other watches at some point or another. Most scuba dives don’t exceed 18m, anyway. Anything with decent gaskets will be fine.
Depends on the brand, and you should follow the manufacturer's recommendations. For some brands, like Hamilton, 50m is merely a suggestion of water resistance. This sub is replete with stories of moisture damage from far less than 50m. For other brands, like Omega, 50m really means 50m of water resistance.
Again, every watch is different but here's a rough guide. Most people don't seem to understand water resistance on watches and somehow think a 50m water can dive 50m under water and be fine
Why do you think you can’t dive 50m under water with a 50m watch? What’s your logic? ISO 2281 says a watch must be able to endure its rated pressure for 10 minutes.
As to the common “static testing” myth, iso 2281 also requires a watch be able to stay waterproof with a 5N force applied perpendicular to the crown while immersed in water, and additionally the movement of the watch under water at a speed of 20 knots would generate an additional pressure depth of 15 feet.
So really moving the watch underwater has almost no impact at all.
Just taken from the first website I googled, explains it better than I can. If you take an expensive watch with only 50m water resistance deep sea diving then you're a braver man than me.
"5 ATM means that a watch can withstand a pressure of 5 bar or a water column of 50 meters. In practice, this corresponds to the pressure of a flowing water jet when washing hands, showering or bathing. 5 ATM does not mean that a watch is waterproof to a depth of 50 meters, but that it can withstand the pressure of a water column of 50 meters. Because when swimming, the swimming movements can cause pressure peaks that are much higher than 5 bar. Due to these pressure peaks, only watches with the designation 10 ATM or higher are suitable for swimming."
Like u/Baridian said, dynamic pressure, as your source mentions is a negligible factor unless if you’re swimming with bionic arms.
[Here:](https://diywatch.club/en/blog/true-meaning-of-water-resistance-rating-on-watch?format=amp)
> But dynamic pressure, contrary to urban myth, is not the main factor in influencing water resistant capability; in fact it only contributes to an increase of 5 metres of additional water depth. The ISO divers’ watches standard dictates that the watch should be able to withstand 125% of the required test pressure as a safety margin against not only dynamic pressure increase, but also thermal shock (think diving from a hot sunny day into icy cold water then back up again), difference in water density (seawater is 2% to 5% denser than freshwater) and degradation of the water seals. These all are contributing factors in determining the water resistant capability of a watch.
[Source 2](https://www.hodinkee.com/articles/seven-dive-watch-myths-deep-sixed):
> The fact is, there is no discernible increase in water pressure on a watch’s gaskets no matter how hard you swing your arms. I’m no physicist, but according to someone who’s done a lot more research than me, you’d have to be moving your arm 32 miles per hour in order to raise the pressure by one atmosphere (the equivalent of an additional 33 feet or 10 meters of depth) and that’s only if the pressure hits the gasket at a right angle, which it doesn’t.
Even if dynamic pressure wasn’t negligible, the idea that you’d need an additional 50m of water resistance because of the force of your arms moving around in the water is a little excessive, given most people rarely dive beyond 10m of water to begin with.
It depends on the brand. If it's a 30m rated digital Casio you can swim with it and it'll be fine. Some watchmakers just make their watches better than others. That's why people recommend 100m as worry free because almost all manufacturers are OK with swimming at that rating. Also, there is no universal rating scale used like for the diver's ISO certification so 50m means different things for different manufacturers.
So if it's a decent brand like Casio or citizen then chances are it'll be OK with swimming.
Scredown crown doesn't actually add much to WR, it just makes it harder to accidentally pull out.
Just follow whatever the brand says you can do with its watches.
It's somewhere in-between the two statements. Some screwdown crowns add to water resistance, and some don't. Not all designs are the same.
[This old WUS thread](https://www.watchuseek.com/threads/watch-engineering-how-does-water-resistance-work.614401) does a good job showcasing some of the different designs.
I don’t take WR too seriously unless it’s on a diver’s watch that’s specifically rated for diving. For example: the old SKX (007, 009, 011, 013) was an ISO rated diver’s watch. That watch stated a 200m water resistance (right on the dial), and, under ISO guidelines, it had to perform at a minimum 125% of that rating to be certified as a diver’s watch. The new 5KX, which looks like the old SKX, states nothing on the dial, but claims a 100m water resistance in the manual. This might be true, but I would not expect it to perform up to this rating because it is not a certified diver’s watch. That said, i’s probably safe to swim with in normal swimming pool conditions. The short, follow the manufacturer’s guidelines and get a real diver if you’re diving.
I’ve swam with my SNK809 Seiko 5 (30m water resistance) Alternatively, I’ve heard internet stories of water/moisture damage from brand new Hamilton Khaki’s (50m)
Water resistance on mechanical watches is highly variable. The terminology used is not standardized - they aren’t using IP ratings for example. “100m resistance” may mean different things between different companies. Your best bet is always going to be to follow manufacturers recommendations.
Yes, for once i forgot to screw down the crown of my skx before getting in the pool for a good 15 mins. No water got in.
SKX are nearly bombproof. I simply love them.
I do most of my scuba dives with a “water resist” Casio F91, and I’ve taken most of my other watches at some point or another. Most scuba dives don’t exceed 18m, anyway. Anything with decent gaskets will be fine.
Depends on the brand, and you should follow the manufacturer's recommendations. For some brands, like Hamilton, 50m is merely a suggestion of water resistance. This sub is replete with stories of moisture damage from far less than 50m. For other brands, like Omega, 50m really means 50m of water resistance.
https://preview.redd.it/6r68hyg5y2wc1.png?width=1024&format=pjpg&auto=webp&s=2f7efb9c4acc7d1a3685d8b97fec05672d99890a
Again, every watch is different but here's a rough guide. Most people don't seem to understand water resistance on watches and somehow think a 50m water can dive 50m under water and be fine
Why do you think you can’t dive 50m under water with a 50m watch? What’s your logic? ISO 2281 says a watch must be able to endure its rated pressure for 10 minutes. As to the common “static testing” myth, iso 2281 also requires a watch be able to stay waterproof with a 5N force applied perpendicular to the crown while immersed in water, and additionally the movement of the watch under water at a speed of 20 knots would generate an additional pressure depth of 15 feet. So really moving the watch underwater has almost no impact at all.
Just taken from the first website I googled, explains it better than I can. If you take an expensive watch with only 50m water resistance deep sea diving then you're a braver man than me. "5 ATM means that a watch can withstand a pressure of 5 bar or a water column of 50 meters. In practice, this corresponds to the pressure of a flowing water jet when washing hands, showering or bathing. 5 ATM does not mean that a watch is waterproof to a depth of 50 meters, but that it can withstand the pressure of a water column of 50 meters. Because when swimming, the swimming movements can cause pressure peaks that are much higher than 5 bar. Due to these pressure peaks, only watches with the designation 10 ATM or higher are suitable for swimming."
Like u/Baridian said, dynamic pressure, as your source mentions is a negligible factor unless if you’re swimming with bionic arms. [Here:](https://diywatch.club/en/blog/true-meaning-of-water-resistance-rating-on-watch?format=amp) > But dynamic pressure, contrary to urban myth, is not the main factor in influencing water resistant capability; in fact it only contributes to an increase of 5 metres of additional water depth. The ISO divers’ watches standard dictates that the watch should be able to withstand 125% of the required test pressure as a safety margin against not only dynamic pressure increase, but also thermal shock (think diving from a hot sunny day into icy cold water then back up again), difference in water density (seawater is 2% to 5% denser than freshwater) and degradation of the water seals. These all are contributing factors in determining the water resistant capability of a watch. [Source 2](https://www.hodinkee.com/articles/seven-dive-watch-myths-deep-sixed): > The fact is, there is no discernible increase in water pressure on a watch’s gaskets no matter how hard you swing your arms. I’m no physicist, but according to someone who’s done a lot more research than me, you’d have to be moving your arm 32 miles per hour in order to raise the pressure by one atmosphere (the equivalent of an additional 33 feet or 10 meters of depth) and that’s only if the pressure hits the gasket at a right angle, which it doesn’t. Even if dynamic pressure wasn’t negligible, the idea that you’d need an additional 50m of water resistance because of the force of your arms moving around in the water is a little excessive, given most people rarely dive beyond 10m of water to begin with.
My Colt GMT has been to 25-28 m on numerous occasions with no issues whatsoever for what that’s worth.
Tbh it’s all pointless because I don’t want sand scratching up my watch so I’m not gonna wear it to the beach anyway.
It depends on the brand. If it's a 30m rated digital Casio you can swim with it and it'll be fine. Some watchmakers just make their watches better than others. That's why people recommend 100m as worry free because almost all manufacturers are OK with swimming at that rating. Also, there is no universal rating scale used like for the diver's ISO certification so 50m means different things for different manufacturers. So if it's a decent brand like Casio or citizen then chances are it'll be OK with swimming.
Depends on the watch and the brand. Some 30m watches are safe to dive with, some 100m watches shouldn’t be worn in the shower.
Just get a screwdown crown and you be fine
Scredown crown doesn't actually add much to WR, it just makes it harder to accidentally pull out. Just follow whatever the brand says you can do with its watches.
Ok if you say so 🥱
He’s right
It's somewhere in-between the two statements. Some screwdown crowns add to water resistance, and some don't. Not all designs are the same. [This old WUS thread](https://www.watchuseek.com/threads/watch-engineering-how-does-water-resistance-work.614401) does a good job showcasing some of the different designs.
Still prefer screw down 😉
That's fair and there are certainly benefits to the screwdown crown itself over a push-pull one.