In the real world, the motion of the wearer's hand through the water creates additional pressure on the watch. Fifty meters is the minimum water-resistance rating a watch should have if you want to wear it while you're swimming. Battery-powered quartz movements are by far the most common type, but you can find some watches with mechanical movements. Sports watches can be made of precious metal, steel, titanium, some other base metal, or plastic. They often have thicker, sturdier cases than dress watches and more rugged styling-thicker bezels, chunkier bracelets, and sometimes flanges that protect the winding crown.
Some watches have synthetic, water-resistant straps.
Occasionally, the straps will come with extenders so they can be lengthened to fit over a wet suit or ski parka. Luminescent hands that can be read underwater or in the dark are another popular feature. Some brands, such as Breitling, Tag Heuer, Omega, and Rolex, offer terrific performance while wielding considerable fashion clout. They also can cost thousands of dollars. The fact that sports watches are being worn almost everywhere doesn't mean that all of them should be.