My Fossil watch says "water resistant up to 330 feet"

antyler

Golden Member
Aug 7, 2005
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Does water resistant up to 330 feet mean that I can safely take a swim to that depth with no problems?

I always assumed that "water resisant" meant like washing your hands with the watch on was safe, but "water proof" meant swimming / diving was ok.

Any difference?
 

mugs

Lifer
Apr 29, 2003
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I don't think you'll find many watches that say they're waterproof. They all say water resistant. If it just says water resistant, it's good for washing your hands and what have you. If says water resistant and has a depth, you can probably take it to that depth without anything happening.
 

Kelemvor

Lifer
May 23, 2002
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Neat quote:

The different levels of water resistance as expressed in meters are only theoretical. They refer to the depth at which a watch will keep out water if both watch and the water are perfectly motionless, says Scott Chou, technical director at Seiko Corp. of America. These conditions, of course, are never met in the real swimmer's or diver's world. in real life, the movement of the wearer's arm through the water increases the pressure on the watch dramatically; so it can't be worn to the depths indicated by lab testing machines.
 

spidey07

No Lifer
Aug 4, 2000
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Originally posted by: Kelemvor

Neat quote:

The different levels of water resistance as expressed in meters are only theoretical. They refer to the depth at which a watch will keep out water if both watch and the water are perfectly motionless, says Scott Chou, technical director at Seiko Corp. of America. These conditions, of course, are never met in the real swimmer's or diver's world. in real life, the movement of the wearer's arm through the water increases the pressure on the watch dramatically; so it can't be worn to the depths indicated by lab testing machines.

Yeah, watches that are truly meant to be worn more than just a few feet below the surface are very expensive.
 

nakedfrog

No Lifer
Apr 3, 2001
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Originally posted by: Kelemvor

Neat quote:

The different levels of water resistance as expressed in meters are only theoretical. They refer to the depth at which a watch will keep out water if both watch and the water are perfectly motionless, says Scott Chou, technical director at Seiko Corp. of America. These conditions, of course, are never met in the real swimmer's or diver's world. in real life, the movement of the wearer's arm through the water increases the pressure on the watch dramatically; so it can't be worn to the depths indicated by lab testing machines.

Well, that's stupid and misleading.
 

antyler

Golden Member
Aug 7, 2005
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Originally posted by: nakedfrog
Originally posted by: Kelemvor

Neat quote:

The different levels of water resistance as expressed in meters are only theoretical. They refer to the depth at which a watch will keep out water if both watch and the water are perfectly motionless, says Scott Chou, technical director at Seiko Corp. of America. These conditions, of course, are never met in the real swimmer's or diver's world. in real life, the movement of the wearer's arm through the water increases the pressure on the watch dramatically; so it can't be worn to the depths indicated by lab testing machines.

Well, that's stupid and misleading.

Haha couldnt agree more. Thats like buying a car that claims to go 150 mph, and then finding out, wind speed and atmospheric pressure, and humidity have to be perfect to reach that speed.
 

ghostman

Golden Member
Jul 12, 2000
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I had a Kenneth Cole "water resistant" watch (not sure of the depth rating). Water got in while I was washing my hands. The watch couldn't have been in contact with running water for more than 1 second. It still worked, but there was condensation behind the crystal. I sent it back to Kenneth Cole and they replaced the watch.
 

HaiBiss

Member
Jul 26, 2008
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it means if you fall 330 feet you will die but your watch will be fine if you land on water.
 

antyler

Golden Member
Aug 7, 2005
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Originally posted by: HaiBiss
it means if you fall 330 feet you will die but your watch will be fine if you land on water.

Hey ill let you borrow it if you want to try out your theory.
 
Feb 10, 2000
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Originally posted by: spidey07

Yeah, watches that are truly meant to be worn more than just a few feet below the surface are very expensive.

Not necessarily. There are a host of 200M-rated divers watches that are available at around $100. You can get a very nice automatic Seiko diver which is perfectly good for SCUBA diving down to 60 or 100 feet for less than $150.
 

LS21

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Nov 27, 2007
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it is *practically* water proof... because i cant see most people diving below 100ft... and if they did they would already have real serious equipment including "real serious" diving watches
 

MetalMat

Diamond Member
Jun 14, 2004
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You need to check the IP ratings on the, if it is IP-68/69 rating you should be gravy.
 

DrPizza

Administrator Elite Member Goat Whisperer
Mar 5, 2001
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Originally posted by: LS21
it is *practically* water proof... because i cant see most people diving below 100ft... and if they did they would already have real serious equipment including "real serious" diving watches

Yep. I can't see 100ft plus swimming in current being anywhere near the pressure experienced at 330ft

Every 33 feet is equal to one atmosphere, so 330 feet is 10 additional atmospheres of pressure. i.e. an extra 147psi. At 100 feet, that's 3 extra atmospheres; roughly an additional 45 psi above surface atmospheric pressure at sea level. I can't see how swimming and current could possibly add 100psi to what the watch case experiences.
 

mpitts

Lifer
Jun 9, 2000
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I think the more important question here is "Do you really need to know what time it is if you are over 100m deep in the ocean?"
 

Rubycon

Madame President
Aug 10, 2005
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100M or "10ATM" rating is common in sports watches. Fine for swimming, snorkeling, bathing, etc. Watches that have screw down crowns should NEVER be submersed with the crown unscrewed. Most digital (watches with push buttons) at 100m rating also require that buttons are NOT pressed when the watch is submersed. Doing so breaches the seal and will allow water to creep in. You may not see it right away but the next day the crystal will probably be fogged up and then you have problems.
 

mugs

Lifer
Apr 29, 2003
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Originally posted by: mpitts
I think the more important question here is "Do you really need to know what time it is if you are over 100m deep in the ocean?"

I think you'd probably want to know how long you'd been under water. I figure that's why dive watches (at least the crappy "dive" watches) have the rotating dial - so you can set it to the time when you went down and tell at a glance how long you've been under water without having to think.
 

spidey07

No Lifer
Aug 4, 2000
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Originally posted by: DrPizza
Originally posted by: LS21
it is *practically* water proof... because i cant see most people diving below 100ft... and if they did they would already have real serious equipment including "real serious" diving watches

Yep. I can't see 100ft plus swimming in current being anywhere near the pressure experienced at 330ft

Every 33 feet is equal to one atmosphere, so 330 feet is 10 additional atmospheres of pressure. i.e. an extra 147psi. At 100 feet, that's 3 extra atmospheres; roughly an additional 45 psi above surface atmospheric pressure at sea level. I can't see how swimming and current could possibly add 100psi to what the watch case experiences.

Physics and fluid dynamics is not your strong point I see? *tongue firmly implanted in cheek.*

Think about it for a while. Push your arm quickly through water and tell me that force isn't way above 1 atm.
 
Feb 10, 2000
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Originally posted by: DrPizza
Originally posted by: LS21
it is *practically* water proof... because i cant see most people diving below 100ft... and if they did they would already have real serious equipment including "real serious" diving watches

Yep. I can't see 100ft plus swimming in current being anywhere near the pressure experienced at 330ft

Every 33 feet is equal to one atmosphere, so 330 feet is 10 additional atmospheres of pressure. i.e. an extra 147psi. At 100 feet, that's 3 extra atmospheres; roughly an additional 45 psi above surface atmospheric pressure at sea level. I can't see how swimming and current could possibly add 100psi to what the watch case experiences.

These kinds of depth ratings are almost invariably overstated.

As a general rule of thumb, a 50M-rated watch is safe to wash your hands with, as it can sustain a splash without trouble. A 100M watch will generally have a screw-down crown and back, and be safe for swimming. 200M is safe for recreational diving, including SCUBA dives to 100 feet. I have taken one of my 200M Seikos to 60 feet without incident.

Typically watches built for diving deeper than that (which is realistically far outside most owner's real-world use) have either passive or active helium-release valves, to allow helium to escape during ascent in a diving bell (deep-sea diving bells are filled with a combination of helium and oxygen). There are actually watches rated for 1000M or more, but they tend to rely on ridiculously beefy cases and crystals and/or are filled with mineral oil to equalize the inside and outside pressure during very deep dives. It's really kind of an academic issue in that no human can survive the pressure at depths like that.
 

DrPizza

Administrator Elite Member Goat Whisperer
Mar 5, 2001
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Originally posted by: spidey07
Originally posted by: DrPizza
Originally posted by: LS21
it is *practically* water proof... because i cant see most people diving below 100ft... and if they did they would already have real serious equipment including "real serious" diving watches

Yep. I can't see 100ft plus swimming in current being anywhere near the pressure experienced at 330ft

Every 33 feet is equal to one atmosphere, so 330 feet is 10 additional atmospheres of pressure. i.e. an extra 147psi. At 100 feet, that's 3 extra atmospheres; roughly an additional 45 psi above surface atmospheric pressure at sea level. I can't see how swimming and current could possibly add 100psi to what the watch case experiences.

Physics and fluid dynamics is not your strong point I see? *tongue firmly implanted in cheek.*

Think about it for a while. Push your arm quickly through water and tell me that force isn't way above 1 atm.

Physics is my strong point - I teach physics. However, admittedly, I haven't studies fluid dynamics in 22 years, nor have I used fluid dynamics in 20 years. Nor do I teach any fluid dynamics, except to explain to my students how Bernoulli's principle isn't enough to make jets fly, no matter what the idiots may say because they remember their 4th grade teacher telling them that it's Bernoulli's lift that keeps them in the air.

However, I'm not sure if you're aware of this or not, but atmosphere's are not a unit of force. Atmosphere's are a unit of pressure. Pressure is force per unit of area. I see that fluid dynamics isn't your strong point either. My, arm has a lot of surface area, so even a small pressure is going to translate into a larger force.

I do realize that there's an increase in pressure on the leading side of an object moving through a fluid (with a viscosity; which is any normal fluid, including air, and which excludes liquid Helium becoming a "superfluid".) Without a difference in pressures front to back, there wouldn't be drag.) And, I recall that there's a difference between static pressure and dynamic pressure. But, I still wouldn't think that the dynamic pressure is that great of a difference.