Photoshop :: Document Border

I use photoshop a lot and have a recurring issue... I often have to edit photos and images which invole me being zoomed in to 300-400%. When zoomed in this far I cannot work out how to view the edges of the document (if Im trying to draw a path or something around an object and the path needs to go out side the bordering edge then come back in) is there a way to do this? I can do it by zooming out, dragging the border box to be larger than the image , but can't seem to do it whilst zoomed in. which is a right pain in the rs.