Hi there, I justed wanted to find out if it is possible to get water to appear in photoreal terrain without using an alpha mask in the aerial image. Can u create and exclude,hydropolys etc or even another bgl to cover the area.

If you put a photoreal image over standard water, it will disappear and become a hard surface , so there is no need for excluding a hydropoly if I understand your question. If you want to pattern or texture the water, say to show underwater artifacts like a reef, the FSX SDK shows how that can be done with a blend mask.