BLUI is a virtual reality program that tallows drawing and sculpting in 3D space using a gestural interface. In this paper, we describe BLUIs use as an interface for annotation, display, and explanation in a variety of scientific visualizations. BLUI can display data from Digital Elevation Models. 3D forms can be positioned and modified, and general navigation can be performed. New lines, surfaces, and point clouds can be drawn and edited. For visualization playback, a line can be chosen along which a virtual camera will fly. Starting and ending positions on this line can be selected. In addition, a 'look at' line with start and end positions can be similarly chosen. A time-scale can then be established for the animation, at which point the user can display the scene from the viewpoint of a virtual camera flying along the first line and looking either straight ahead or at a point moving along the second line.