The X-21 is a surfboard made for your intermediate to high performance surfer and made for waves that are waist high to over head. This board was designed to be a high performance surfboard for good waves at home, on the W.Q.S, and on the W.C.T. This board is one of Xanadu's most popular models as it is one of the driviest short boards in our line. The X21 has a curvier entry rocker and a flatter exit rocker that creates masssive amounts of speed and drive. This surfboard has heaps of single concave mixed with volume under the front foot that creates a virtual speed monster under your feet. When the WCT guys order boards this is quite often what they get. You would be surprised how many of them are on this board!