A 0.5mm titanium neoprene layer is both comfortable and warm. Wear it under your normal sailing gear for extra warmth - remember layers are better than thickness! Titanium neoprene acts in a similar way to a survival blanket, a titanium impregnated relective layer is sandwiched between the neoprene and the interior nylon lining, this lining reflects body heat on the inside back to the body.