I just didn't think there was something right about the nose of the Mark 1. It was nice, but tended to pearl and cut underwater at times if you didn't hold the board right. The new outline has a wider nose with a more hull shaped belly. The Mark 2 also has about 3/8" more rocker than the previous model which not only helps with the pearling but just fits onto a steeper wave face better than the Mark 1 did. We got rid of the wing and just pulled in the width of the tail to compensate. Of course we kept the fish tail on the standard model, but we'll offer custom tail shapes like a crescent, square, diamond, and squash. I recommend the swallow tail because of the hold it gives you on the face, but if you want a tad more volume, you may always opt for something else.