Talk:Water Resistant mark

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Does anyone know where iso standards can be looked up for free?

Itn't it a bit ironic that you need a watch that says it can resist water 100 meters deep before you can swim in a 3 meter deep pool with it?

[edit] The definition is wrong?

I don't understand, if this mark means, that watches able to resist some water pressure, why they are unable to resist it actually while scuba diving? If they unable, hence either this mark means something else, or the pressure while scuba diving is higher than while testing. But second is may be truth only on Jupiter :), so probably the first is right. So, the definition of term is wrong, it seems to me! Excuse my English. Dims 08:34, 4 February 2006 (UTC)

• Yes, it would be nice to see an explanation of why, for example, a 30M rating doesn't correspond to a depth of 30 metres underwater, and where the rating actually comes from. That's what I came here to find out. Funkdafied 07:53, 7 March 2006 (UTC)

• If you read the article carefully, it says that 30M rating for example referrs to static pressure. That means that if you for example teleport the watch to 30M depth, it will widthstand the pressure. However, if you just swim with the watch, when you do a stroke it will be faced with much higer pressure, possibly equivalent to 50M+. Just think, as you swim, don't you feel the pressure of the water when you move your arms? That is the pressure the watch will experience, and it won't be equivalent to just 1M of static water pressure. I cannot give you a formula (it depends on the shape of the watch), but a watch in 1m depth moving at 10km/h, will probably face more pressure than if it was static in 50m depth. But anyway, the equivalence to depth is comfusing, I guess it all started for show and for giving something closer to common understanding than bar measurements. Dkechag 17:05, 14 May 2006 (UTC)

• Thank you. I don't think that explanation was there when I first posted the comment, but its good to see that it's there now. Funkdafied 02:11, 10 June 2006 (UTC)

It seems to me, that dynamics does not explain situation. It seems, that it can't be true, that some human moving can change pressure, equivalent to several times static pressure. The pressure at the h meters depth approximately is h/10 atmospheres. So, it is one atmosphere at 10 m. So, if you say, that moving hand equivalent to arising pressure to 50 m, it means, that moving hand making pressure of 4 atmospheres! It looks unreal! Dims 21:40, 15 August 2006 (UTC)

Why is it so hard to believe? 4 atm is about 60PSI - that means a pressure of 60 pounds (assuming the seal of the watch is 1 square inch). That's no problem for a human. And in fact the seals of a watch are much smaller then 1 square inch, they might be a tenth of that, so it's very easy to apply that much pressure to them (6 punds). Ariel. 21:26, 19 September 2006 (UTC)