Overlapping but not identical concepts. I suppose you could say the x bow is a refinement of an inverted wave piercing bow. The thing that's distinct about the

Overlapping but not identical concepts. I suppose you could say the x bow is a refinement of an inverted wave piercing bow. The thing that's distinct about the x bow is it has reserve buoyancy in both pitch directions, but is fine and wave piercing at the waterline. This gives advantages above an inverted bow in general.