Unlike regular swimsuits, which are designed mainly for the aesthetic appearances, swimsuits designed to be worn during competitions are manufactured to assist the athlete in swim competitions. They reduce friction and drag in the water, increasing the efficiency of the swimmer's forward motion. The tight fits allow for easy movement and are said to reduce muscle vibration, thus reducing drag. This also reduces the possibility that a high forwards dive will remove a divers swimwear. Starting around 2000, in an effort to improve the effectiveness of the swimsuits, engineers have taken to designing them to replicate the skin of sea-based animals, sharks in particular.