Contact angles using water were measured on five coatings used on aircraft. These coatings are very uniform spatially but do exhibit hydration, meaning their contact angle changes as a function of exposure to the vapor of the test fluid (i.e., water). Therefore each contact angle was measured as a function of time, with t = 0 corresponding to the first contact of the water with the dry surface. Two contact angles can be identified: an initial angle and a steady-state angle. These surfaces equilibrated in about 15 seconds, as can be seen from the representative graphs of contact angle versus time presented below.