The notches I have been using on this cabin and the one I built in Alabama are called half dovetail. They interlock with no need for nails and any water that may get to the notch drains outward to the outside face.
To cut the notches now, I just have to mark a line down the center of the log and mark the length. Then I attach the jigs with some screws and am ready to go. The chainsaw bar has a couple of small blocks of wood attached to prevent the chain from touching the jig.