Hoodoo,
That sounds like what I would think of as an upside down saber, and I know just what you mean with the Navigator. I just played with that grip again, and I don't like it with the Mouse. The grip does not feel secure, and the pad of my thumb is very close to the edge, and wants to slip that direction.
My inclination for gutting a deer at least would be to run my index finger down the spine of the knife all the way to the point. That way I have to full edge to work with, but have the point covered so it can't snag anything under the skin I don't want to cut.
Mike