Many of our contemporaries bathe in ponds and pools without taking off their watches. Some are just used to this accessory and never take it off, some for protection purposes, for example, on a crowded beach, so as not to be stolen, and so on.
The fact is that in some types of watches you can swim without fear that they will stop. These are the so-called waterproof watches, which are made using special technologies, they allow moisture not to penetrate into the watch case when they are immersed in water.
In the manufacture of water-resistant watches, materials and technological methods are used that make it possible to maintain a very high tightness of the watch case and, therefore, make it possible not to remove it when immersed in water.
In order to visually understand whether a watch is waterproof or not, you can look at the back of the watch. As a rule, there is an inscription WATER RESISTANT, or WATER RESIST, and sometimes WR (in some cases this inscription is also written on the dial). But this means, rather, some protection from high atmospheric humidity and dust, but not from water! Near the inscription, a number is also indicated, which shows some strengthening of the protective properties. For example, the numbers 3atm (or 30m) say that you can count on protection from moisture and dust, however, direct contact with water for such watches is dangerous and unacceptable!
The numbers 5atm (or 50m) indicate that you can swim, but without diving. And finally, if the figures are 20atm (or 200m), then you can scuba dive in this watch.
In general, when sailing with the watch, it is recommended to choose models with a screw-down case back and a screw-down crown. However, even watches with a high degree of water resistance, having a metal case, should not be used in situations with a relatively sharp temperature change, for example, when taking a shower at home or after a pool, swimming in the sea during a beach holiday, visiting a steam bath or sauna. And yet, it is not recommended to take a shower or bathe in a bath at any hour, because when heated, different materials expand differently and geometry is lost, as well as soap, shampoo, foam and many other detergents corrode gaskets, this violates the geometry and because of this, the watch loses its protective properties.
After all, a watch is an accessory, not a part of your body.