Suggestion strategy:

• Shell size:

  • Determined by measured foot-lengths and selecting next shell
    
    

• Shell volume:

  • Determined by statistic category of foot-widths:
    normal, wide, narrow, ...
    
    

• Customization for skill-levels:
  
  

  • “Advanced” instead of “Sportive”:

    • Shell sizes around one size larger

    • Shell volumes slightly wider
      
      

  • “Beginner” instead of “Sportive”:

    • Shell sizes around 1.5 sizes larger

    • Shell volume about one category wider