Use the highest percentage zinc you can find and tolerate.  I often use the Dermaquest Zinclear SPF 30 with 18.6 zinc.  It also comes in a tinted form and the tint is a more medium shade.  It's expensive so just use it on your face or key areas.   In addition, with high sun situations like cycling for hours, hiking, etc., you can layer over it the Colorescience  Sunforgettable powder which is more sweatproof and water resistent.  If you are going to be in the water a long time, then use a water resistent sport sunscreen as a base, like Elta MD Sport.   Dr. I