All ION RASHGUARDS are made of highly elastic SpanFlex UV jersey. The hand feel of this supreme material makes the difference! They can be used to protect you from the windchill effect, UV radiation and abration but also work as a thin extra layer underneath the wetsuit.
- What to wear under rashguard shirt? If you are in a warm water - nothing, because then you would defeat the purpose.
- Do rash vests keep you warm? No, its only for UV protection and level 1 abbrasion protection.
ION wetshirts are certainly one the best rash guard manufacturers.