Hi, I'm new to this game and having a few problems with my water in FSX

. Basicaly, when I'm flying the water changes in big squares to an almost white colour and is also affecting the land scenery. It's ok from a distance but as soon as I fly over an area it gets covered by this. Has anyone else ever had this problem and does anyone know how to get rid of it... I'm not much of a computer person so don't really know if anything needs adjusting etc. Any help is greatly appriciated...