

The Death Of The Dive Watch: The Rise Of Dive Computers And The State Of Tool Watches Today

In the 1970s, the battery-powered quartz movement dealt a near-death blow to the mechanical watch and many of the companies that built them, a cautionary tale well known to watch enthusiasts as the "quartz crisis." A less-talked-about story though is how the rise of the digital dive computer has had a similarly lethal effect on the venerable dive watch, rendering that most utilitarian of tool watches a mere relic almost overnight. Of course, dive watches are still popular today, perhaps even more than they were when divers used them to track their bottom times in the 50s, 60s, and 70s, but now they are more symbols of a lifestyle than a true tool for most. Few non-divers understand how a dive computer works or why it dethroned the mighty dive watch from the frogman’s wrist. Here’s a brief overview to bring you up to speed and a look at where the dive watch sits today.

For a diver, it's all about time and depth. For every foot of depth, there is a set length of time you can remain until you need to decompress before returning to the surface. This has to do with the absorption of compressed nitrogen into body tissues that expands as you surface, not unlike opening a shaken soda bottle. Stay too long, too deep without decompressing and you risk decompression sickness, more poetically known as "the bends" for the way it makes its sufferers double over in pain. Since the earliest days of diving, divers have relied on a set of tables developed by scientists and the US Navy to determine those "no decompression limits." These tables, used with a dive watch and a mechanical depth gauge, were the primary tools a diver used for the first half century of SCUBA diving. For divers who planned to exceed the no-deco limits, there was the even more complicated task of calculating decompression stops. Some dive watches put decompression tables right on the dial. Dive computers changed all that.

A dive computer makes use of an electronic depth sensor to indicate current and maximum depth, as well as dive time, water temperature and sometimes even the amount of air left in a tank. A computerized algorithm uses the time and depth data to calculate no-decompression limits and remaining time at any given depth. The real magic of a dive computer is that it does all these calculations on the fly, adjusting for an undulating dive profile rather than merely relying on maximum depth like divers used to have to do. It also takes into account the accumulated nitrogen in body tissues from multiples dives in a given day and the so-called surface intervals between dives, when a diver "off-gasses." All of these functions are contained in a watch-sized package that can be worn on the wrist or integrated into other gauges connected to the diver’s tank.

Given these features, it’s no wonder the dive computer replaced the dive watch/depth gauge combination. In fact, dive computers are often required by dive operators for the safety of its clients and you’re about as likely to see a dive watch onboard a dive boat as you are a two-hose regulator or rubber wetsuit – unless there’s a HODINKEE reader diving that day, of course.

Still, the saying "two is one, one is none" applies to diving as much as any other potentially dangerous activity involving expensive gear. This is a version of the "n + 1" rule that says that not having a backup instrument is as good as not having any at all. So the dive watch does still have its place, as does a mechanical depth gauge. The fact remains – a simple Seiko mechanical dive watch will outlast a battery-powered, plastic-cased dive computer, even if it does keep worse time. And batteries do tend to fail at the worst possible moment.

While dive computers really came into common use in the 1980s and 90s, there were crude early attempts as far back as the 1950s. Not surprisingly, the development of the dive computer was driven by the military. While the US Navy was outfitting its divers with Tornek-Rayville Fifty Fathoms and Rolex Submariners, it was also quietly seeking ways to track the “nitrogen loading” of its divers. The earliest example of a dive computer was arguably the Foxboro Decomputer, an analog clunker that indicated the relative safety of ascending using a simple scale that went from “Safe” to “Danger.” Not exactly confidence-inspiring. Others came and went with limited success. Divers still tended to prefer their old watches and depth gauges to these new devices, one of which was nicknamed the “Bends-o-matic” due to its inconsistent accuracy. In the late 60s to 70s, dive computers went electronic but battery life was miserable, especially in cold water.

It wasn’t until the 1980s that technology caught up and dive computers became reliable, accurate and accessible to the diving public. Most people credit the Orca Edge as the first viable dive computer. Its design was intuitive and ergonomic but it was incredibly difficult to build and didn’t calculate decompression times so if a diver stayed past a no-deco limit, he had to do some quick math or risk the bends. Finnish compass brand Suunto broke into the dive watch game in the late ‘80s and has been a leader ever since, with innovative features like electronic compass and wireless tank pressure monitoring and sleek sport watch designs. And in 1987, UWATEC introduced its Aladin computer which quickly became a favorite of divers everywhere. In a bit of poetic irony, UWATEC has the distinction of being Swiss Made, replacing countless dive watches from the same homeland.

While there are still a handful of old school holdouts and Luddites who prefer to dive using a gauge, a watch, and dive tables, most acknowledge that the dive watch’s era of practical use is over. Still, the dive watch has its place as an emblem of the golden age of discovery and the derring-do of the early days of underwater exploration. As useful as a dive computer is, let’s face it, no one talks about the “Mil-Suunto” or the “Bond UWATEC.” I’ll still proudly and stubbornly wear a dive watch on one wrist when I dive and my digital dive computer on the other.

The dive watch is dead. Long live the dive watch.