It's Complicated: Dates on Dive Watches
It took Rolex 15 years to add a date to the Submariner, it took me nearly as long to appreciate it.
Though still beholden to international standards in terms of basic functionality, the vast majority of dive watches today see depths no greater than that of the hotel swim-up bar. As technology has evolved, the need for an analog watch as a key piece of dive kit has all but come and gone allowing once brutally utilitarian functionality to give way to flashy design and quality-of-life additions. Hell, you can even find precious metal and two-tone models for the Jacques-Cousteau-meets-Patrick-Bateman crowd. No judgement. Perhaps chief among the topside-minded features of many modern dive watches is the ever-present (and much maligned) date window. It’s a common sentiment, among the internet watch cognoscenti at least, that a dive watch doesn’t need a date. The thought is that a date complication on a dive watch is like an altimeter on a car dashboard—a feature that presents data that is totally superfluous to the instrument’s intended use. I understand this perspective, I’ll even go as far as saying I used to share it. It wasn’t until I spent some time with (and more importantly, without) a date complication on a dive watch that I would learn to appreciate it.
Released in 1954, the design of the Submariner 6240 was spartan. Its intention was simply to be legible at depth and in low light conditions by divers who needed to precisely measure time against meticulously planned dives. For the uninitiated, while in the drink, a diver’s blood and tissues take on nitrogen from their breathing gas. Nitrogen makes up approximately 78% of air by volume; at the surface it’s harmless but as pressure increases underwater the level of residual nitrogen in the body must be carefully managed. This is accomplished by staying within NDLs—no decompression limits—or by taking decompression stops underwater which allow a diver’s body to gently off-gas before returning to the surface. Each dive involves careful planning in advance and calculations which factor in the gas mix and time spent at each depth. As they say: plan the dive, dive the plan. While dive plans and a thorough brief are still very much a part of diving today, they were paramount in the 20th century and without the guard rails of highly advanced modern dive computers, considerably more prone to human error. Deviation from a dive plan or miscalculation can have dire consequences including decompression sickness, also known as DCS or “the bends.”
After the waterproofness of the case, perhaps the most important hallmark of a dive watch is the bezel. By rotating to meet the minute hand, the bezel tells at a glance the amount of time that has passed. This feature goes back to the very first of the modern divers, the Blancpain Fifty Fathoms (released a year prior to the Submariner in 1953.) It’s a common misconception that dive bezels are used to monitor the amount of air remaining in a diver’s tank, in reality that’s the job of a SPG, submersible pressure gauge. Rather, a dive bezel helps a diver track time spent at certain depths to ensure adherence to the dive plan. It also makes for a great way to time pasta on the stove. As with all tool watches, the name of the game in dive watch design is utility. It’s easy to understand why the Submariner opted for a simple time-only design and would stay in the Rolex catalog, virtually unchanged, for the next 60-some years. It had everything a diver needed, until it didn’t.
As professional divers plunged deeper and deeper the amount of time that would need to be spent decompressing beneath the surface grew longer, limiting the time a diver could work at depth. This constraint lead to experimentation into different breathing gasses as well as the advent of saturation diving. It was discovered by Dr. George Bond, a US Navy researcher, that there exists an upper limit to the amount of nitrogen that can be absorbed by tissue before reaching a plateau, being fully saturated. This means that divers could be pressurized in specialized hyperbaric living chambers, leaving to perform their subaquatic duties before returning to the chamber after their shift. After days or even weeks the aquanauts would be slowly decompressed before reuniting with their crew-mates at surface pressure.
An unexpected quirk of such dives was that helium from the chamber could encroach into a watch and cause the crystal to pop off as a diver returned to surface pressure due to the gas rapidly expanding within the case. Famously, COMEX, a French diving company, sought a solution from the Swiss watch industry. Omega’s response was a study, helium-proof monobloc case design with the PLOPROF (a portmanteau of plongeur professionnel, professional diver). Rolex’s solution was the addition of a small spring-loaded one way valve on the case flank that would allow helium to escape. The helium escape valve, HEV, would be commercially included in the Sea-Dweller 1665 in 1967. In addition to greater waterproofness and the addition of the HEV, the other striking modification to the Sea-Dweller from its precursor was the addition of a date window at three o’ clock. For saturation divers living beneath the surface this must have come as a godsend. A saturation diver’s responsibilities are different during a dive than a “normal” diver, tethered to a vessel with support crew monitoring and without the need to worry about NDLs, a saturation diver’s focus is on the task they’re performing such as conducting scientific research or performing maintenance on subsea infrastructure. As such, a saturation diver’s watch became as much a tool for tracking the passage of time inside the habitat as outside.
Following in the Sea-Dweller’s footsteps, two years later in 1969 Rolex would release the Submariner Date 1680. The Submariner Date was not designed for the same rigors of the Sea-Dweller and was not intended for use by saturation divers. Rather, it was a tacit acknowledgment by Rolex of the utility offered by a date complication to the average Joe. Even though recreational divers track the passage of time underwater in minutes, not hours or days, the availability of the date at a glance provided useful information for logging dives after the fact and, indeed, for everyday life. By the late 60s, wearing a sports watch outside of its ostensible intended setting was commonplace, perhaps most famously illustrated by the appearance of a Submariner 6538 on the wrist of Sean Connery as James Bond in Dr. No in 1962. This is doubly true today. Mainstream divers began adopting the use of dive computers as far back as the 80s meaning dive watches have since become all but obsolete. Granted, some old school divers and enthusiasts weirdos like myself may insist on bringing an analog dive watch along for redundancy. After all, as any good instructor will teach you, when it comes to dive gear - two is one, one is none.
My first “serious” dive watch was an Omega Seamaster 300. A vintage-inspired take by the brand on their historical dive watch catalog complete with faux-patina (let’s put a pin in that for another time), sans date. Even though at the time I had no aspirations as a New York-dwelling-subscription-box-startup-marketer of becoming a diver I was drawn to the sturdiness of the case and the classic design, and yes, the fact that it was a “proper” diver without a date. That watch wouldn’t go on to stick long, eventually making room for an Explorer. It wasn’t until years later that my name would come up at my local AD for a Submariner Date that I would even consider a dive watch with a date. I eagerly picked it up. In the intervening years I’ve worn the bejesus out of that watch, even getting SCUBA certified with it on my wrist. Call it Stockholm syndrome or a genuine appreciation for the feature but every time I go from wearing my Sub or Sea-Dweller (both with dates) for an extended stint to a watch without I find myself glancing at my wrist when writing a check, scheduling an appointment, etc. to check the date before sighing and begrudgingly checking my phone.