A swimsuit can be worn as an undergarment in sports that require a wetsuit such as water skiing, scuba diving, surfing, and wakeboarding. Swimsuits may also be worn to display the wearer's physical attributes, as in the case of beauty pageants or bodybuilding contests, and glamour photography and magazines like the annual Sports Illustrated Swimsuit Issue feature models and sports personalities in swimsuits.
There is a very wide range of styles of modern swimsuits available, which vary as to body coverage and materials. The choice of style may depend on community standards of modesty, as well as current fashions, and personal preferences. The choice will also consider the occasion, for example whether it is to be worn for a passive occasion such as sunbathing or for an activity such as surfing or competition. Swimwear for men usually exposes the chest, while suits for women usually cover at least the breasts.
Rayon was used in the 1920s in the manufacture of tight-fitting swimsuits, but its durability, especially when wet, proved problematic, with jersey and silk also sometimes being used.
In the 1930s, new materials were being developed and use in swimwear, particularly latex and nylon, and swimsuits gradually began hugging the body, especially women's swimsuits.
In western culture, men's swimsuit styles include boardshorts, jammers, swim trunks, briefs or "speedos", thongs, and g-strings, in order of decreasing lower body coverage, and Women's swimsuits include one-piece, bikinis, or thongs. While they go through many trends in pattern, length and cut there is not much modification to the original variety of suit. A recent innovation is the burqini, favored by some Muslim women, which covers the whole body and head (but not face) in a manner similar to a diver's wetsuit. These are an updated version of full-body swimwear, which has been available for centuries, but conforms with Islam's traditional emphasis on modest dress. In Egypt, the term "Sharia swimsuit" is used to describe full-body swimwear.
Swimsuits can be skin-tight or loose-fitting. They are often lined with another layer of fabric if the outer fabric becomes transparent when wet.
Swimsuits range from designs that almost completely cover the body to designs that expose almost all of the body. The choice of swimsuit will depend on personal and community standards of modesty and on considerations such as how much or how little sun protection is desired, and prevailing fashions. Almost all swimsuits cover the genitals and pubic hair, while most except thongs or G-string cover much or all of the buttocks.
Most swimsuits in western culture leave at least the head, shoulders, arms, and lower part of the leg (below the knee) exposed. Women's swimsuits generally cover at least the areola and bottom half of the breasts, but some are designed for the top part of the swimsuit to be removed. In many countries, young girls and sometimes women choose not to wear a swimsuit top, and this can vary with the occasion, location, age, etc.
Both men and women may sometimes wear swimsuits covering more of the body when swimming in cold water (see also wetsuit and dry suit). In colder temperatures, the swimwear is needed to conserve body heat and protect the body core from hypothermia.