Enhanced buoyancy for swimmers with heavy legs Front and back panels feature 3mm Yamamoto #39 SCS Side panels boast 5mm Yamamoto SCS Aerodome SCS Nano coating for reduced drag Comfort-focused waistband design The Buoyancy Shorts were first developed by Zone3 back in 2008. The original invention of this product was made using a 5:3mm thickness smoothskin material but due to their overwhelming popularity, Zone3 have now released a more buoyant and lower drag focused design called 'The Premium Option'.