I have just come back from a regatta in St Barths in the Caribbean and I took my Sharkskin over. I wore the Shortsleeve Chillproof under my team T shirt and it was amazing. Getting fully wet on the bow of a 147 foot boat and being totally warm. I love not being restricted by a jacket! Some of the guys on the boat really like Sharkskin for kite boarding as well as sailing.