Wouter's dead on, good description.

Its less about wave piercing and more about moving the volume down low so that the boat can be pressed harder downwind. Remember the Acat doesnt have a spin, so the main drives the boat downwind. Anyone who's gone downwind or on a hot reach in a uni-rig without a spin knows that the mast wants to push forward at the top, and the bows want to stick in and stop. So its more about preventing a pitchpole than wave piercing thru waves even though thats how this bow is described.

The bows also wont stick underwater when you bear away or if you press them hard downwind like a flat top deck will. Once a flat top deck goes underwater its all over, you either stop or pitchpole. I've actually done bear aways too agressively and the sterns come out of the water the boat bears away with the bows underwater and just the tips of the rudders in the water. Pretty scary the first time I did that. But it didnt stop, it just kept going.

Bill