For years, some of our competitors have been making claims that their designs are immune to pitching. "They don't pitch", are the exact words of one seller of DreamBoats. Charitably, I'll say that the person making this claim was confused. All marine vessels operating on the surface pitch. Cruising sailboats operate on the ocean surface which is almost always subject to waves, and waves make a vessel pitch. End of story. Submarines don't pitch when they are submerged and SWATH vessels pitch very little due to their extremely small waterplane area. EVERYTHING else pitches in waves!
You can make argument that one design pitches more or less than another. OK, fair enough. That is a point worthy of discussion. It is not a simple subject and probably the reason why people have been able to ventilate pure hype for so long and get away with it.
When a catamaran encounters a wave at the bows it will first immerse the bows more deeply which starts them rising upward due to the increased buoyancy of the immersed hull. As result the boat will rotate (pitch) positively. If it did not pitch then the boat would just continue driving the bows deeper and deeper into the wave such that the wave crest would wash over the top of the boat, burying the cabin, filling the cockpit, etc. So the ability to rotate or pitch is an essential function. The boat must be able to pitch upward in order to sail over waves.
After passing the wave crest the bows naturally will pitch downward as they fall into the wave trough. Often the forward third of the hull will be completely out of the water. What happens next is critical. Will the hulls do a slamming belly flop when they contact the dense ocean surface or will they more gently part the water avoiding the crash landing?
A surprisingly small flat area is all that is needed to slam. When hull bottoms are rounded off in the typical U section advocated by some "race boat" designers there exists a flat spot along the center line, and this is all it takes to cause a slam. This is evident in many advertising photos where spray is being ejected sideways from the hull forebody. What the still photo does not convey is that a half second before the hull slammed the wave surface.
Since the beginning CW Designs have always incorporated deep "V" sectioned bows to make abrupt landings as soft as possible. Instead of a bone shuddering "BANG", the re-entry is more of a cushioned "Whoosh". Sailing upwind, a cat will encounter a wave about every 5 seconds. If that causes a slam-bang every five seconds, that is 12 slams in a minute, 720 slams per hour, 2,880 slams per four hour watch! Certainly I exaggerate, but you get the idea. Slamming and pounding is not only uncomfortable, but can be dangerous in a cruising boat because it causes crew fatigue. Anything that can be done in the design stage to minimize this should be done.
The cost for obtaining soft landing comfort is a minute amount of additional hull wetted surface (a fraction of 1%) AND a slight increase in the amplitude of pitch because the cushioned impact requires that the hull not stop suddenly when it hits the water. There is an old saying that the surest way to stop a pitch is a slam! Well it is much better not to stop the pitch suddenly and allow the shape of the hull to cushion the impact instead.