A water resistant watch is the one made to prevent water from entering. A water-resistant case has joints which are made to prevent moisture from entering.
There are several features to make a water resistant watch. The most important one is the gasket, which also called 0 ring, is made of rubber, nylon or Teflon. Normally, the gaskets will be sealed at the joints where crystal, case back and crown meets watch case. If the watch has chronograph function, the chronograph pusher will also have gasket. In addition, water-resistant watch cases are lined with a sealant, applied in the form of a quick-hardening liquid, which keep water out.
The thickness and material of watch case is also a important factor in determining whether a watch can be worn underwater safely. The case must be sturdy enough to withstand pressure without caving in. In general, it means to steel case, titanium case or steel case plated with gold. Solid gold cases can be water resistant provided their sufficient thickness.
As opposed the pushed case back, a screw-in case back also contributes to a watch’s water resistance in waterproof watch supplier
. A screw-in crown also prevent water getting into the case through watch-stem hole. It is a common feature of many dive watches. When it is screwed down, it forms a water tight seal, which like the seal between a jar and its lid.
Literally speaking, the above are the most common designations for water resistant watch.