Rash vests (also referred to as rash-guards and rashies) should really be called "Anti-rash" as they are used to stop the wetsuit from chaffing the skin, usually around the neck or under the arms. Some people also have an allergic reaction to latex/neoprene products. In any of these cases a simple Lycra Rash Vest can be the answer.

During Colder months the Thermal Rash Vest is more popular. There are several types on the market. Ingredients include Metalite/Thermolite (0.5mm of titanium-neoprene), polyplush and polypro. These garments are worn under the wetsuit and can boost the warm of the suit considerably.