solardiver
33
Nov 2, 2017
The description alludes to the fact that it is a dive watch. Although I'm sure it is an excellent watch, it is not a watch for diving. 100 meters is only good for swimming at best. 3 ATM 30 meters/100 feet Everyday use. No swimming. 5 ATM 50 meters/165 feet Short periods of swimming. No diving or snorkeling. 10 ATM 100 meters/330 feet Swimming and snorkeling. 20 ATM 200 meters/660 feet High-impact water sports and some diving. Diver 200+ meters/660+ feet Scuba diving. Passes ISO regulations.
MarkSA
49
Nov 2, 2017
This is simply incorrect unless Seiko is lying about the watch's waterproofing. As a scuba diver using compressed air, you start to get nitrogen narcosis (drunk on the nitrogen gas in your breathing air) at around 30m (100ft), with very serious effects (e.g. starting to offer your mouthpiece to surrounding fish, with subsequent drowning...) at 42m (140ft). In addition, hypoxic breathing gas (mixed gas diving) is required below 60m (200ft) to lessen the risk of oxygen toxicity (oxygen poisoning, causing muscle spasms so strong that they can break your bones), so this watch absolutely can be used as a divers watch unless Seiko is wrong about it's depth rating (or you are using a professional diving suit and your watch is strapped to the outside of it... in which case you might want to look at their 1000m watches). There are videos on YouTube where Seiko tests its diving watches to well beyond their ratings, to such an extent that they stop working because the pressure on the case causes it to bend and stop the mechanism, so I very much doubt that they are lying about their depth ratings here...
solardiver
33
Nov 2, 2017
I don't know why Seiko and other manufactures use these numbers. If your watch says it's water resistant up to 30 meters, that means you can dive with it down to 30 meters, right? Wrong. You can destroy your watch that way. Though the dial or back of the case may give you a number, that number probably doesn't refer to in-use scenarios, or is a reflection of a standardized water resistance classification. When in doubt, always err towards the dry side Water Resistant 100 Meter watches. This is snorkeling territory. A watch with 100 meters of water resistance has no problem hanging out in the water for a while, and will even be fine on an extended snorkeling excursion. Diving, however, should still be out of the question. As diver, I have had good 200 meter watches flood at 100 feet.
MarkSA
49
Nov 2, 2017
If you had 200m watches fail at 100ft you were either wearing a fake Rolex, you didn't screw in the crown properly, or you hadn't serviced the watch for years.
You will see in this article that two Seiko 1000m divers watches failed at 3200m+ and 4200m+ (quite unbelievable performance!). https://www.hodinkee.com/articles/what-dive-watch-depth-ratings-really-mean-and-whether-you-can-trust-them
"The Internet being what it is, someone got curious about this issue and ran the actual numbers. As it turns out, movement does indeed increase actual pressure, but to a trivial degree. The relevant forum post on Watchuseek includes this remark: "Without repeating all the calculations here (they involve denominators and the Greek alphabet and are PITA to type out), at a depth of 330ft(100 m) and moving your arm at 3 ft/sec, the dynamic pressure is in the order of magnitude of 0.14 feet of head or 0.04% of the depth. Even assuming you could move your arm at 20 ft/sec (14 mph!) the dynamic pressure is only about 6.2 feet of additional depth (<2%)."
solardiver
33
Nov 3, 2017
The figures I gave are standard acceptable ranges for water resistance (Google it). And no, I don't wear fake or cheap watches.
MarkSA
49
Nov 3, 2017
"I don't wear fake or cheap watches" So that leaves the other two options...
The figures you quote are just nonsense.
arp415
133
Nov 5, 2017
If you had a rope rated for 500 lbs you would think you should feel comfortable hanging 500 pounds from it. How ever if you have ever done any rigging you know to never hang more than 250 lbs from a 500 lb line.
I wonder if the same is true of depth ratings.
As to your googling of the math, it does not seem to take into account impacts (watch against rocks, dive equipment), or the effects of the watch being worn by a sad and bitter troll.
MarkSA
49
Nov 6, 2017
We are talking about diving with a watch rated for 100m to 200m. That is 300ft to 600ft. If you are scuba diving below 150ft you are starting to get into pretty dangerous territory, so normal scuba diving with a 100m rated watch IS like hanging 250lbs from a 500lb line. If you knock a watch rated at 1000m against a rock or dive equipment at 5 ft deep, you run the distinct danger of shattering the crystal and flooding the watch, so that is no argument. As also pointed out, moving the watch against water at a speed of 14mph gives a dynamic pressure of 6.2ft. Water skiing at 45 mph and falling and hitting the water at that speed is: 1) likely to be seriously painful or result in bodily injury and 2) gives a dynamic pressure on the watch of roughly 20ft deep, which it should easily handle. Increasing that speed to 90mph (40ft dynamic presssure on your watch) is very likely to kill you but leave your 100m rated watch ticking away merrily as you sink to the bottom. When you reach 300ft deep it might stop working...
So, once again, the figures quoted are nonsense.
arp415
133
Nov 6, 2017
As long as a watch is accurate enough to let you know when the sun is coming up you should be fine.
Also congrats on your our success in the class action suit against Lowes and Home Depot over the ever deceptive “2x4”.
Please write your congressman/congresswoman to help bring about change in the watch water resistance ratings racket. Bringing it to their attention will be even more effective than complaining about it on massdrop.
MarkSA
49
Nov 7, 2017
Who is complaining? I‘m just pointing out the obvious i.e. that Seiko, as a reputable watchmaking company that has been in business for decades, makes a quality product and that you can believe what it says about the depth ratings it gives its watches. Also pointing out that the original poster doesn’t have a clue when he states that you need a watch rated to 200m to do high impact water sports(!) or that you can only swim and do snorkeling with a Seiko watch rated at 100m. Quoting opinion like that just shows that he has not done his research and is just believing anything he reads on the Internet as being truthful. In reality, incorrect information like he posted is probably being put out there by watch retailers trying to sell you more watch than you need in order to boost their profits (and who should be avoided unless they can show you actual tests that support their viewpoint!).
solardiver
33
Nov 7, 2017
You would think that a watch that is marked as water-resistant to 100m would mean that you could safely swim to depths of 100m while wearing it. You can't.This is because the watch has only been tested once using static pressure on a newly manufactured model, without taking into consideration rapid changes in water pressure and temperature in seawater over a period of time along with the resulting aging of the seals. So be careful.
MarkSA
49
Nov 7, 2017
If you don't service your watch regularly, you can absolutely not expect it to remain waterproof, so that takes care of your 'aging of the seals' point. With regards to rapid changes of water pressure (that presumably will exceed the 100m rating of a watch...), please explain how this can occur when scuba diving...
arp415
133
Nov 7, 2017
Lol MarkSA lives in a perfect world where everything makes sense and is logical. That is why he chooses to come to the Massdrop discussion to air his grievances and belittle people who try to provide useful information lol.
arp415
133
Nov 7, 2017
Have you ever considered that a 100m rating just doesn't mean what you want it to mean?
MarkSA
49
Nov 7, 2017
Ok, this has gone on long enough. I ask you simple questions and you don’t respond to them but come back with insults. No further response will be given to your last word, which I am sure you will send.
arp415
133
Nov 7, 2017
Bwahahahahahahahaha!!!! you've got a wicked sense of humor dude, i dig it
warchyld67
Dec 28, 2017
you guys are missing the POINT....water...RESISTANT...not water {PROOF.) instead of arguing it on mass drop...go visit a SEIKO/ CITIZEN...etc..DEALER..and ask them what water RESISTANT to 100 meters MEANS..i think you will be surprised what they tell you
Bend94
4
Jan 14, 2019
Actually any rope that is rated for 500lb actually will have been tested to atleast twice that more than likely for rigging ropes a 5X safety factor is standard. Now talking watches. When engineering your water resistance I would imagine that you would put atleast a factor of safety (f.o.s./s.f. is how many time greater your product requirements your product is actually engineered to survive) would probably be at least 2 meaning a 100m watch would actually be designed to survive 200m. Now look at production if you give something a 100m rating you know that in manufactuing you are going to get a normal distribution of results. So depending on what you standards are if I wanted 99.9% of my products to excede my rating I would have to have close to 4 standard deviations from my average to achieve this. Now if I have really bad quality control i.e. 10 m std dev that would meen that my average actual water resistance would have to be 140m 99.937% of watches beign able to survive between 100 and 180m, but actually you would have a success rate of 99.99685% because any watch with a greater ability than 100m would pass quality control. If you tighten your control to say 2m std you would have 99.99685% of all watches would achieve your 100m rating, just costs time and money to tune production. When I worked as a quality engineer we actually had 6 sigma on each side, which equates to 0.999999998% of all product will meet your requirement. TLDR: Designs have a safety factor normaly at least 2. Then in production normally 99% of your product has to meet or excede the requirement which equations to 4+std dev above the requirement. So your 100m watch probably can go to 150m easy.