Difference between Waterproof Watches and Water Resistant

To tell the truth, no watch can guarantee perpetual waterproofness. But have you ever stopped to think about what those words actually mean? The two terms are often used interchangeably, although they have completely different meanings. Simply put, a waterproof luxury watch can withstand a certain amount of contact in a certain time or condition, and a “waterproof” watch should theoretically be waterproof.
One of the major causes of “waterproof” replica watches failing is the degradation of seals designed to ensure a gapless construction. Such seals, which are normally made from a type of rubber or plastic, can be weakened or eaten away in extreme heat or cold. One of the reasons it makes sense to have your watch serviced every few years to ensure that the seals are functioning as they should. All decent watchmakers will perform a dry pressure test on your replica watch before returning it to you, ensuring your peace of mind for at least another few years.
Temperature fluctuations can cause real problems for the water-resistance of a timepiece. In warm weather, components expand. That coupled with active submersion or moving water is just about as bad a combination as a watch could hope to meet. And so very few watch brands risk anointing their wares “waterproof” – however, one notable exception is Rolex. Thanks to the provenance and performance of the fake Rolex Oyster case, true waterproofness has been guaranteed down to 100 meters and deeper since 1926.
There are three ways to express the depth to which your watch has been tested. The most commonly used unit of measurement is “meters.” Perhaps the second most common way to communicate depth rating is through atmospheres. Atmospheres are expressed by the abbreviation “ATM.” One atmosphere is roughly equivalent to 10 meters, so 10ATM is the same as 100M. 
The third way to express water resistance is “Bar.” The bar is a unit of pressure, not depth. Although this is a common topic of conversation among collectors and watchmakers, it is not often printed on the face of a watch. One bar is equal to one bar, so 10 bar is equal to 10 atmospheres and 100 meters. The most common depth levels are 30M, 50M, 100M, 200M and 300M. In addition to these depths, there are depths of 500 meters, 1,000 meters, and even deeper, but they are usually only used for very specialized diving tools.
So what do these common ratings mean in real life? Do you feel safe jumping over puddles, into showers or swimming pools? Hopefully you won’t find yourself wanting to shell out in a hot tub, but if this sounds like something you might do, you might want to invest in a fairly heavy outfit.