PBB Plus Base Layer SystemPBB Plus Base Layer system from OThree is STAGE ONE in our multifunctional, interchangeable heating system. This PBB Plus Base Layer Set comprises of: Top, Salopette, Socks Male or Female, Unisex Top Drysuit and Base Layer are Inextricably Linked Internal thermal insulation for dry suits, we feel, is one of the most misunderstood elements of dry suit diving. It is fundamental for divers to understand thermal layering and its buoyancy implications when