The watch you're supposed to buy
Somewhere around the fifth year of a career — associate to something with a title, trainee to something with a floor — a watch tends to appear. Black dial, black bezel, steel bracelet, the date at three behind a lens nobody asked for. Nobody has to tell him which one. He already knows.
Your correspondent bought his own version of it at twenty-six, for reasons that had very little to do with diving and a great deal to do with what the desk next to his was wearing.
The Rolex Submariner is not a bad watch. It survives being dropped, banged and forgotten in a gym bag; it will comfortably outlast the career it's rewarding. None of that is really why most of the people wearing one bought it. Ask, and the diving rarely comes up. It's the watch that means arrived — chosen for what it announces, not what it does.
A decision that size, made because it's the default one, is still a default decision. The people who actually asked what they needed a watch to do tend to end up somewhere else.
"The Rolex you should have bought" is a case study in the other way of doing this. Its owner didn't need a watch that meant anything. He needed to know what time it was in the city he'd just left and the one he was about to land in, at the same glance. The GMT-Master's second hand does exactly that and nothing else — a complication built for a specific inconvenience, not a specific department.
From "The Rolex you should have bought" — bought for a time-zone problem, not a dress code.
If it's actually diving
For the smaller number of people for whom the water genuinely is the reason — who dive, rather than would dive if the trip ever came up — the Submariner isn't obviously the more considered choice even inside its own category. The Sea-Dweller carries a helium escape valve the Submariner has never needed and never had, and is rated to more than four times the depth. The reference 116600, specifically, ran without the cyclops lens magnifying the date — a detail nobody at sixty metres is reading anyway — for three years before Rolex added one and discontinued it. It's harder to find now, for exactly that reason.
Its predecessor, the reference 16600, on a wrist. Photo: hypo.physe, CC BY-SA 2.0.
If the Submariner is still the right answer — and for plenty of people, it genuinely will be — the research doesn't have to stop at the reference number. Production years are public record. A steel Submariner exists from the year someone was born, the year they made partner, the year a kid arrived. Finding it takes a weekend and some patience instead of a walk into a boutique.