My apologies if this has been discussed many times, but I don't understand the appeal of high depth ratings and helium escape valves on dive watches. I am a certified diver, but can't see a reason for needing greater than a 50m depth rating. Even the Advanced Open Water Diver certification only gets you to a recommend 30m limit. The vast majority of dive watch owners will only swim or snorkel with their watches. Then 99% or more of those that dive will ever go beyond 40m which takes you into decompression diving. I have dove a fair bit and been around a number of divers. My dive instructor was the only person I know to dive with Tri-mix (which includes helium).

It seems to me that a well maintained 25m rated watch is all most people need, and almost all divers would be good with 50m. Is it the mystique? I have a watch that could do amazing depths even if I won't.

 

I think people are under the impression that a larger depth rating means that a watch is even more water resistant at lesser depths and for longer periods of time than a watch with a lesser depth rating. Like, "wow, if my Planet Ocean can go down 600m, no matter what I expose it to up here on land, it will always be waterproof. No need to ever have the seals checked. And why bother to avoid detergents or other things that can put extra stress on the gaskets?" That's my impression at least––and to some extent I can't disagree. I'm also open water certified and never go below 40 meters, but I still wouldn't wear a watch rated only to 50m.


It's so waterproof, guys!

 

Personally, I just like knowing that it could. I suspect others do too.

It’s like buying a laferrari but only driving it in the crowded streets of Beverly Hills. The car won’t ever go above 45, but it’s nice to know that it could go over 200. I think this is pretty much the definition of luxury, which in the grand scheme of things, these watches are.

 

Well, ya' never know when you might want to take a dip in the Marianas Trench.

Good question wagudc. I've wondered the same thing. I've supposed that it was for bragging rights or for true dive watch geeks.

I don't dive. I don't even allow my few dive watches to go out in the rain. Never felt the need to wet the watches.

 

If you read up on how depth ratings are determined, you'll probably find that a 50m rating (with brand new seals, tested in a controlled static environment) really doesn't have the margin of error you'd want to have. But I certainly agree that a skin-diver watch with a 150m rating, is plenty good enough for any recreational diver. Commercial/technical divers are an entirely different story, of course, but they usually don't wear watches exposed to the environment anyway.

The other side of this is the marketing angle, and the connection of marketing to technology, which has a long history in horology. If you look at advertising of pocket watches and wristwatches, you will constantly see that manufacturers used technological developments to market watches, even when many of the advances had little practical benefit. This is the thinnest watch, this is the smallest watch. This is the watch with the most complications. This is the watch with the most jewels. This watch can withstand the highest magnetic fields. Etc. It's no different with depth rating. It's fun and interesting to have a watch with a 1000m depth rating, and it's a way for a manufacturer to demonstrate a certain type of superiority.

 

Same appeal of a car that goes 200 mph but gets driven around town I guess.

 

I am somewhat certain that depth ratings in watches don't work in this way. In other words if a watch is rated for 30m , it doesn't actually mean that can dive up to 30m depth. To my understanding it only means the watchs can handle lights splashes (washing hands, light rain).

As far as I know only a 100m depth rated watch is safe to swim and do some submersions. A 200m and up depth rating in a watch is what makes it usable in dives.

I think it has something to do with the watertightness test and the pressures use in those tests (3atm/bar, 5atm, 10atm etc) and to what "depth" that said pressure correlates underwater.

To my knowledge you cannot take a 3atm = 30m depth rated watch to 30m underwater, let alone to 1m.

I am no expert on this matter and happy to learn more about this if I somehow got this totally wrong.

 

I posted this in another thread, but back when I dove I used analog gauges and this cheap Casio I found on the sea floor during a training dive. I got 25 dives on it with no issues. None were deeper than 30m. It is rated to 50m.

 

I think you can but people are overly cautious. I know of plenty of people who've been swimming in their Speedmasters but I'm not sure I'd do it.

 

I definitely would not dive in my Speedmaster. I think screw down crown and pushers are a must for diving.

 

Agreed but it can take a lot more than just splashes.

 

I agree completely. For a nice watch a bigger margin is a good idea, but as I said above I had no issues regularly diving with a cheap 50m rated watch.

 

A depth rating is not a suggestion - if a watch is rated to 50m, that means it has been pressure-tested to that depth. And if its seals are in good condition etc, it will handle that depth without issue (usually more, in the case of ISO certifications).

 

Oh, ok, so depth rated and water resistance is not the same thing?

A simple google google show several sources that show recommendations for "30m water resistant" watches that only resists splashes and not 30m underwater.

Makes sense if I got the "depth rating" and "water resistance" mixed up.

 

Your kinda missing the point mostly because you don’t understand that lessors water ratings have a tendency to loose wr easier. A watch is only water resistant until it isn’t. Example a Speedmaster, you knock one of the pushers the wrong way and you lost your WR and would have no idea. Something that’s not going to happen on planet ocean chrono, which is somewhat unique in that you can actually use it’s pushers underwater at depth, something very very few chronos can do.

higher depth ratings tend to be more robust with better seals and higher tolerances no no pushers. Plus back ups like screw down crowns that cover for worn crown seals.

 

The way I've seen it explained is that while pressure is more or less staic under water while not moving the moment you move your arms to swim or do anything else the pressure increases on one side while it drops on the other, as when a propeller or wing cuts through the air.
This effect is magnified greatly in situations when powered devices are used or a diver is towed on a sled.
A watch rated for 100 feet might fail in 30 feet of water if the diver is engaged in strenuous activity or uses a sled or other transportation. The deeper you go the more the effect is magnified.
A watch rated for 100 meters (330 feet) should hold up to all you can throw at it down to 100 feet or a bit more.

 

I think they now make it possible for all those desk divers among us to move their office work several feet/meters deeper..
.

 

Exactly.

And just like any average driver who tries to take their car to the limit will very quickly find themselves, like any diver who tries to test the limit of his 600 metre watch, completely out of their depth.

(two puns there, you figure'm out)

 

I use my fish tank as my 1000m watch box



Even a Toyota Camry speedometer goes to 220km an hour

and swimming with a Speedmaster

Why not, 50m is 50m what’s 1 or 2 going to do......

 

What About Dynamic Pressure? Myth

https://forums.watchuseek.com/f17/water-resistance-myth-vs-reality-159142.html


Only a issue if the above sled is going 300km an hour.

The minute you swim or move under water it changes pressure is nothing but a myth as you couldn’t move your arms quick enough to cause any change in pressure above or below water......