The shower cleans what the pool cannot easily remove
Before entering an Icelandic public pool or hot spring, bathers are generally expected to shower thoroughly with soap, without a swimsuit. The point is not modesty or ceremony: it is to wash sweat, skin oils, cosmetics, and other residue off the body before those substances enter shared water.
A swimsuit can make that wash less effective. Fabric covers parts of the body and can hold onto dirt or detergent, so rinsing off while wearing one does not clean the skin beneath it. Showering undressed lets bathers wash those areas directly—especially the places that need the most careful cleaning.
Cleaner water with less reliance on chemicals
Every person who enters a pool brings in small amounts of organic material. In a heavily used pool, that load can build up and make water treatment harder. A thorough shower reduces what swimmers add, helping facilities keep the water clean without relying as heavily on disinfectants as they might otherwise need to.
That does not mean the water is untreated or that a shower makes it sterile. Pool operators still manage water quality; pre-swim washing is one practical step that helps the whole system work.
The rule also explains the layout of many facilities: changing areas lead to communal shower rooms, and the route to the bathing area passes through them. The shower is part of entering the water, not an optional rinse afterward.**
