FEATURE: Water Resistance...

A few weeks ago I was watching a video on the Theo and Harris You Tube channel, I don't know if you are familiar with Christian and his channel but he's a young guy who seems to have quickly made a business for himself selling vintage watches.... so far, so good. Vintage isn't my thing, but his channel is still okay in parts because he doesn't stick exclusively to vintage, for instance today he did a pretty good job of ripping Breitling's new Navitimer 8 to shreds, and deservedly so it has to be said.

However, in the video I watched a few weeks ago he was talking about water resistance and made it perfectly clear that he had no idea how water resistance ratings on watches worked. I can't remember exactly what he said but it was something along the lines of 30M is fine because I'm never going deeper than that. Which is worrying from a man selling watches, is it not?

I left Christian a comment (as did other people, unsurprisingly) and he responded saying he felt very silly and he went on to address his folly in a video he made about water resistance and how the ratings work. To be fair, the ratings are bloody stupid and are wide open to misinterpretation, especially for the average Joe whose interest in wrist watches doesn't extend much beyond needing to know the time.

So, while I appreciate that most of you will already know this, for the benefit of any that aren't aware, a 50M rating DOES NOT mean you can take it to a depth of 50M. The problem is 'pressure', you could theoretically place that watch in a tank and fill the tank very carefully to a depth of 50M, but if you move the watch in the tank you increase the pressure and the watch will most likely leak.

Essentially, it goes like this:

30M or 3atm: Suitable for everyday use, splash/rain resistant. Not suitable for showering, bathing, swimming, snorkeling, water-related work, fishing or diving.

50M or 5atm: Suitable for swimming, white water rafting and fishing. Not suitable for diving and snorkeling.

100M or 10atm: Suitable for recreational surfing, swimming, snorkeling, sailing and water sports. Not suitable for diving.

200M or 20atm: Suitable for professional marine activity, serious surface water sports and skin diving. Not suitable for deep water diving

500M+ or 50atm+: Suitable for deep water diving.

So if you've got a lovely new Carrera with a display caseback and it says 100M water resistant on the back, you can go swimming in it, but you can't dive with it, this is because diving and moving in the water in general increases pressure on the seals.

And the other thing to bear in mind is that if you want to maintain your water resistance rating you should have your watch tested annually because the seals can dry out and fail. It is also important to note that chlorine, bathing products, some cosmetics and heat cycles can all play a part in degrading the seals in your watch.

But of course, even if you follow all these rules, there's still always the possibility of human error. Some watches, like my Aquagraph (above) have visible warnings to help you avoid costly mistakes, here the crown has a yellow (or sometimes orange) band that becomes visible from the front side of the watch when the crown is unscrewed.

But not every diver has this and if you really want to be safe then you need something like the latest Rolex Submariners which have a triple-lock system which keeps the water out even if the crown is unscrewed. Providing, of course, that it's been serviced properly...