Boy's black short sleeve rash vest by Osprey. A rest vest is a really useful wetsuit accessory to prevent you getting rash and rub when surfing, kiting, bodyboarding and other water sports. A rash vest can go under your wetsuit and provides a sleek soft layer between you and your wetsuit, to minimise abrasion, especially around your neck. You can also wear a rash vest in the water when it’s too warm for a wetsuit, and it will prevent the wax and sand on your surfboard from causing a rash.