Guys you need to remember that an infinite plane is INFINITE! You can't resize an infinite plane. What you will need to do is this. Create your volume infinite plane for the ground. Take a square boolean and strech it as far as you can see. Position the boolean to where it will cut the infinite plane. Set the plane to positive and the boolean to negative. Group them now. If you want infinte water, create an infinite water plane and place it just below the ssurface of the infinte ground plane! That will work! :)