Castelli vela vestcastellis vela vest is an amazingly lightweight and compact vest constructed from leading sail making fabric used in americas cup racing this windproof and waterproof fabric uses dyneema yarns for near bulletproof strength dyneema if you are unsure is a white core yarn used in rock climbing ropes and bulletproof vests this fabric comes straight from sailing where light weight and extreme tensile strength come together in a sport where cost doesnt matter but winning d