By the late 1980s, the advent of the digital dive computer sounded the death knell for the traditional dive watch. Nowadays, nary a diver on a boat can be seen wearing an analog watch, despite its continued benefit as a backup device or for a navigational aid (timing swim distances, etc.). A good dive computer will calculate no-deco limits in real time, adjusting for time spent at various depths during a dive, the use of enriched air mixes that lengthen no-deco times, and will also alert you when it’s time to ascend or when you’re going up too fast. More advanced ones will calculate decompression times, even allowing for gas switches mid-dive, and read the amount of gas left in your cylinder.
But through this brief look at the history of dive watch markings, we can see how problems were solved along the way, by analog means only, and how, despite their seeming simplicity, dive watches have been useful to take divers on some of the world’s greatest undersea adventures.