# Is 100m Wr Good Enough For Swimming?



## kwahoo (Feb 19, 2005)

Some people have claimed that it is dangerous to swim with a 100m WR watch, even though the standards say that this rating should be fine, and I am wondering if there are specific reasons why, or just general caution. I don't mean to criticize, only to find out if there is an important factor I'm missing.

My question was inspired by several recent posts, including this thread on water resistance:

http://www.thewatchforum.co.uk/index.php?s...=44204&st=0

I expect this has been discussed quite a bit, but I couldn't quite find an answer using search.

Specifically, some people have claimed that 100m WR (= 10 bar of pressure) is not safe for casual swimming or going off a diving board. But 10bar is 10X atmospheric pressure and nearly 10X the pressure if you just submerse the watch under a few feet of water. It is still about 5X beyond the static pressure at 10m of water (already deeper than any pool). Clearly the watches can sustain the the additional water pressure of swimming motions in any pool or ocean, unless you are the Incredible Hulk. How much extra pressure is generated by a jump off of a casual diving board, I don't know - it's just a matter of the velocity at which you enter the water. Without data on this, I can see why people want some extra margin of error - clearly a 200m WR watch must include the ability to withstand that.

Of course, gaskets wear out on any watch. Having some additional margin of error helps here too. But I don't know how much a stronger WR rating helps here--it has to do with how the gaskets age. Ultimately, no matter the rating, you can only be sure of its actual water resistance if you do periodic pressure testing.

So I am wondering if this is the extra safety margin is the reason people prefer 200m WR - or whether there is something I am missing. Ok, flame away now. 

Thanks,

/K

ANY watch


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## thunderbolt (May 19, 2007)

The rule of thumb I use is that if a watch has a screw down crown and is a minimum of 100m W/R then I'll wear it in the water, but if not then it doesn't go anywhere near water. Simples.


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## thedburgess (May 15, 2009)

When I was a kid I always swam in the sea and pools with a casio 100m and never had a problem with it. Now though even without any problems with a 100m I opt for 200m +

I think it should do what it says on the watch. A 30m isnt waterpoof then why put water proof if its going to get buggered by doing the washing up.

I have a chart that came with one watch this is what it has to offer.

3atm/30m suitable for dishes, rain and washing the car

5atm/50m suitable for dishes, rain, washing the car, taking a bath and swimming in a pool

10atm/100m suitable for dishes, rain, washing the car, taking a bath, swimming in a pool and snorkelling

20atm/200m suitable for dishes, rain, washing the car, taking a bath, swimming in a pool, snorkelling and diving

Now I don't remember what watch this came with and may be relevant to that make and maybe different companies have different guides for their WR rating just to make it more confusing.


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## pugster (Nov 22, 2004)

i think it comes down to do you want to chance a 100m watch in a pool that cost Â£XXXX when all you need to do is get a 200m one, that being said , i'd be happy to swim in a pool with a watch that cost a fiver regardless of depth rating and just throw it away later if it leaks


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## zed4130 (Jun 25, 2009)

i had one of the original G-shocks and i swam and dived in the sea with no problems other than the colour going funny after a while, my 100m rotary swiss commando has a screw down crown and has never leaked in the sea snorkling etc, plus going down to the deep end of my local swimming baths, i usualy take my watches off though , i like them to be at least rain proof lol


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## kwahoo (Feb 19, 2005)

pugster said:


> i think it comes down to do you want to chance a 100m watch in a pool that cost Â£XXXX when all you need to do is get a 200m one, that being said , i'd be happy to swim in a pool with a watch that cost a fiver regardless of depth rating and just throw it away later if it leaks


But what makes 200m safe and 100m not? The 200m watch can suffer gasket wear and decay too. And if you assume the gaskets are good (because it's new or recently serviced or tested or whatever makes you say they are good), then they're good and 100m is safe.

Don't get me wrong, I find myself leaning toward 200m too because it somehow feels safer -- but I want to know, are we all being suckered?

As for screw down crowns, there's nothing magic there. It does avoid accidentally releasing the crown, but I believe it actually puts MORE wear and tear on the crown gasket. Not a problem if you aren't continually resetting it, though.

/K

/K


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## jasonm (Nov 22, 2003)

That thread you linked to was the baby thread..

This one is the daddy 

http://www.thewatchforum.co.uk/index.php?s...ater+resistance


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