We study the at geometry of orthogonal projections of a generic space curve to planes. For a single projection, we do this by considering submersions on a (singular) plane curve. This is an alternative method to the classication of divergent diagrams carried out in [9]. We redraw the bifurcation diagrams of the orthogonal projections of space curves adding the information about their at geometry. We also study the duals of the projected curves and the way they bifurcate as the direction of projection varies locally in S 2 .