No one driving... too many vino's and was afraid of DUI.
Middle mouse button will zoom in/out and pressing-hold will let you rotate the picture.
For all the other naysayers, this is not intended to spruik SketchUp, but rather how to navigate the 3D model if you decide to look closer into it and find yourself ankle deep in water. A SketchUp model can reveal many hidden intricacies of a build that are harder to put into words.
If your first cut is too short... Take the second cut from the longer end... LBD