Between the years 2008 and 2009 swimmers across the globe broke 130 world records. The reason for that were the so- called High- Tech swimsuits. However, in 2010 the International Swimming Federation FINA decided to ban these swimsuits from all their competitions. In general, the physic of swimming can be divided into three main parts: buoyancy, drag and propulsion.The role of buoyancy in swimming is dependent on the individual body composition and relies on Archimedean principle. Although some theories state that the suits allow better buoyancy, a lot of studies could not prove that there is a benefit in buoyancy of High-Tech swimsuits.Total drag is differentiated by the physical principles of each resistivity. Pressure- or form drag is created by differences in pressure of the swimmers front and backside, and it is dependent on water management. The suit leads to muscle compression and a streamline-like body shape, and therefore reduces the pressure drag. Friction drag is created by a discrepancy of speed of the around flowing water layers. Due to the similarities of the swimsuits surface and a shark, surface drag is reduced. The drag of the waves emerges from the original level in front of and behind the swimmer because of the elevation in water mass. The swimsuits had no positive effects on wave drag. In swimming, the propulsion is based on two principles. Firstly, with the support of the principles of paddling and the suppression of the water mass, propulsion according to Newtons law “Actio es Reactio” is generated. Secondly, the principle of buoyancy creates a drift because of the shear force that is acting in swimming direction. The High- Tech swimsuit has no positive effects on propulsion directly. The physical benefit is limited to the decrease in drag.