A wetsuit works when a thin layer of water is trapped between the wetsuit and the skin. The body temperature of the diver heats this water creating a nice insulation from the colder surrounding water. A properly fitting wetsuit relates to the effectiveness of the insulation. Your wetsuit should fit snug and still allow a full range of motion. The Akona Skin Suit provides a 2nd layer of thermal protection under your wetsuit. It also assists in donning your thicker wetsuits.