How deep can water resistant watches go?
Essentially, if a watch is water resistant to 1 atmosphere (ATM) it is water resistant to 1 bar, or 10 meters, or approximately 33 feet.
|WATER RESISTANCE GUIDE|
|50m/165ft - 100m/330ft||Light poolside swimming|
|100m/330ft - 200m/660ft||Swimming, snorkeling, showering (no hot water)|
|200m/660ft - 500m/1650ft||Impact water sports such as board diving and scuba diving|
|500m/1650ft+||Appropriate for serious deep water diving.|
A watch stamped with "Water Resistant" means that it is humidity-protected. It can endure a bit of water splashes from washing your hands or being caught in the rain. However, water resistance does not mean you should swim or shower with your watch on. Water is the biggest enemy of a watch.
With all factors considered, a 100M rated watch, in mint condition, can safely go to 100M depth without failing (most recreational scuba diving goes to a maximum depth of around 45M). That's the factory standard.
As is so often the case in Germany, there is also a DIN standard for this. 30 minutes in 1 metre water depth and 90 seconds in 20 metres water depth, a watch should remain functional in order to be classified as water resistant according to DIN 8310.
Rolex Oyster Watches
With the exception of the Rolex Cellini, all modern Rolex watches are fitted with the Rolex Oyster case. This guarantees water resistance of up to 100 meters (330 feet) for the following models: Rolex Datejust and Datejust II.
All Rolex wristwatches are 'waterproof' to depths of at least 100 metres for Oyster Perpetual models, and 50 metres for the Cellini model.
In Recreational diving, the maximum depth limit is 40 meters (130 feet). In technical diving, a dive deeper than 60 meters (200 feet) is described as a deep dive. However, as defined by most recreational diving agencies, a deep dive allows you to descend to 18 meters and beyond.
CX Swiss Military Watch 6,000m (20,000 Feet) The CX Swiss Military dive watch currently holds the world record as the only mechanical dive watch that is certified water resistant to a depth of 20,000 Feet. Emphasis on mechanical since other deep dive watches are certified to go deeper but they are oil filled quartz…
Amongst technical divers, there are divers who participate in ultra-deep diving on scuba below 200 metres (656 ft). This practice requires high levels of training, experience, discipline, fitness and surface support.
What watch can go the deepest underwater?
In 2019, the Omega Ultra Deep Professional was strapped to the exterior of a submersible vessel that touched down on the floor of the Mariana Trench (the deepest trench in the world), clocking a depth of 10,928m and beating Rolex's previous record by just 12m.
The production version works 6,000 meters below sea level, setting a new bar for the industry. An unfortunate thing happened in the testing of a prototype of Omega's new Ultra Deep diver's watch.
So a 300m watch has been subjected to 375m (or, more accurately, 3.75ATM of pressure) in testing. In direct contrast to watches marked 10m, 30m or 50m, a dive watch marked with 100m of water-resistance or more is absolutely capable of being submerged in the stated depth of water.
General water resistant watches should not be used underwater. 100 meters/ 328 feet/ 10 bar: are often called divers watches and can be used for snorkeling, swimming, and other water sports, but not high board diving or sub aqua diving.