diving at 17 degree is real torture. I wore a rash guard + heat guard + 3mm long suit and 3 mm shortie. First dive of the day you will not feel anything. Is the second dive when your body get wet and re-entry into the cold water, then u know what is call chilled water. It has come to the extend that on my third dive, I have to pee inside to warm myself. yes sound disgusting, if not I will have to make the whole group abandon that dive.