New gel coat composition, in particular new marine gel coat compositions, a process for their manufacture as well as their use to coat surfaces of articles exposed to light, water and solvents. The gel coats incorporate a precipitated silica having A BET surface of from 150 to 250 m2/g A SiO2 content of more than or equal to 98.5% by weight A Na2O content of less than or equal to 0.5% by weight.