The purpose of this study is to investigate a new approach in creating sizing systems of wetsuits for the surfing industry. A good sizing system focusses on the balance between fit, comfort and functionality. The research provided a theoretical framework that assesses the natural body shape variations within a given user population. The focus is on gaining the highest level of coverage through determining the right body type classification. As a result digital mannequins are created that can serve as representation of body types associated with a specific apparel sizes. This research addresses the sizing of wetsuits for the European market. It incorporates the investigation of the full human torso and extremities. This study uses the 3D anthropometric data from the CAESAR project. The population contains 1255 Dutch and 801 Italian body scans. The population is filtered to gain an accurate representation of the surfer body types. Furthermore different methods are investigated in classification of body types considering the prioritization of different anthropometric dimensions. The resulting population is divided in groups that would be suitable for a specific wetsuit size. These populations are merged into average and extreme 3D mannequins that can be used in 3D apparel design software such as Clo3D or Optitex. These mannequins provide an accurate representation of specific wetsuit sizes and can be used to digitally asses the fit of the product. To make the mannequins suitable for 3D pattern drawing and flattening applications, the mannequins are reduced in size according to the desired tightness of a wetsuit. Current sizing charts on the market have been set up with the use of surveys and optimized based on customer feedback. It might not consider the entire population outside their current customer population. Furthermore these sizing charts are created based on one dimensional measurements and therefor do not capture the full shape of the human body. A new approach that uses 3D anthropometric data can give new insights in designing the right product dimensions for the highest sizing coverage. The use of 3D mannequins will increase the amount of anthropometric information that can be used in the apparel clothing industry. The approach is demonstrated on Italian and Dutch subjects and provides a good coverage for the European market. It can be trivially extended to other populations when the necessary data is available. @en