There may be no more misunderstood type of timepiece than the dive fake watches, which is strange because it is arguably also the most popular kind. Dive watches are loved for their ruggedness, their sporty good looks, and their perceived ability to make almost anyone wearing one a little more like Dirk Pitt or James Bond. Much of this perception comes from the images and hyperbolic copy we see in watch company marketing, that depicts a stubbled, black-clad diver emerging from the sea wearing his 2,000-meter oversized watch. But the realities of dive watches are often much different from those many of us have come to believe. And the less dives watches are used for their original purpose, the more pervasive the myths become. Here are some of the most common dive watch misperceptions and the reality hiding behind them.
The rotating bezel helps you keep track of how much oxygen you have left.
There are a few things wrong with this statement, which I’ve taken verbatim from a recent dive watch press release, and you don’t have to be a diver to know that. First of all, the timing bezel, while versatile, is fairly dumb. It does one simple thing – track the passage of time, up to an hour. You could stare at your bezel for an entire dive and still accidentally suck your tank dry if you don’t also check your submersible pressure gauge regularly. Now, you could approximate how much air you’ve got left if you know your air consumption rate; i.e., how much you breathe in a given amount of time, but that’s more useful for creating a dive plan than it is reason to ignore your pressure gauge.
The other thing wrong in this statement is the use of the word, “oxygen” which I see misused far too often with reference to diving in general. Most recreational divers breathe compressed air – 21% oxygen, 79% nitrogen and trace amounts of other gases – but to breathe pure oxygen below 20 feet of water depth is toxic and can cause convulsions, and usually an unpleasant death by drowning.
A dive bezel can be used for a lot of things – timing total dive time, decompression stops, swim distances and surface intervals. But until watchmakers figure out how to sandwich a pressure gauge inside a watch case, your dive watch is never going to tell you how much oxygen – or air – you have left.