Through the years, watches have been not only useful devices to tell the time but fashionable accessories as well. Modern technology has allowed watchmakers to craft timepieces in a way that makes them aesthetically appealing, more durable, and with even more uses than ever before. Some are made to be especially resistant to water, and some are even completely waterproof. The most renowned watch makers sold by Jacobs the jewellers in Reading—brands like Tag Heuer, Cartier, Longines, Bremont, Bulgari, and others—are known to make such kinds of watches.

What Your Watch Water Resistance Numbers Really Mean

If you look at the opposite side of a watch’s face, known as the case back, printed on the reverse are numbers and words that identify it as either water-resistant or waterproof. Sadly, too many people get the two confused too often. Before you go showering, swimming or even diving with your trusty timepiece around your wrist, get to know what those markings at the back of your watch mean.

Water Resistance

Most modern watches feature water resistance at varying degrees. The watch is made water-resistant through the use of a component called the gasket that prevents the water from penetrating the watch. The watchcase, which is made of sturdy materials, is designed to withstand both low and high levels of pressure when submerged underwater.

The label at the back of the watch should indicate a depth limit from 30 metres to 200 metres and some Tag Heuer, Cartier watches or Bremont watches even go to 300m.  The term “water resistant” means that a watch will still fare well when exposed to a small amount of water. A water resistant watch that claims to be resistant to 30 metres should not be taken diving, as it can only resist splashes of water at best. Meanwhile, a watch with 50 metres of water resistance can be taken for a swim but only in moderation, and strictly no diving. Water resistance of 100 to 200 metres is ideal for snorkeling and swimming but not diving into the depths.


The only truly waterproof watches are diver’s watches. These pieces are designed to withstand high levels of pressure and are also resistant to corrosion brought about by salt water exposure. Some will have a helium gas release valve built into the case. Look for the “ISO 6435” mark on the dial or on the case. The ISO standard guarantees that it can withstand being submerged in water in the indicated depth number. The depth number of diver’s watches vary from 100 metres to 200 metres. These watches are remarkable for their shock and magnetic tolerance, making them perfect to take on extended hours of diving.

Of course, if ever one is in doubt, just contact the team at Jacobs Reading jewellery store you acquired the watch from to provide you with the necessary information.

(Source: What Your Watch Water Resistance Numbers Really Mean, Supercompressor)