"Drag is what holds. Fins are drag, V is drag, etc. Those big soft rails on > a mat are great for neutral handling. Suction on a big convex surface. > Water is able to wrap around the rails rather than be released too early.>>> aloha Tom, Yes, drag is what holds, but how that song is played is what really counts... Unlike all other surfcraft, in the esoteric world of modern, ultralight surfmats, there are very few design compromises that relate to precise contours, simply because the wave itself... is always the shaper! To be specific, modern high performance surfmats (since 1982) with their very thin and supple, nylon fabric running surfaces need only the minimum drag to provide control. Close observation of these surfmats accelerating across a wave at trim speed most often reveals the tell-tale, low wake, with water peeling off the exposed bottom and outside rails, rather than wrapping around them... a clear indication of efficiency. Skilled mat riders never inflate their craft anywhere near full air capacity, and instead fine-tune the mat`s volume, flotation, control and speed by subtle manipulation of the internal air pressure between waves (with the deck valve), as well as while riding, by increasing or decreasing their hand/arm grip. In turn, this causes significant changes in internal pressure, making the inside rail and thickness flow either fuller, or flatter. The result, at velocity, is a surfcraft which is always changing its template, rocker/torque, thickness flow and rail contours in direct response to the continually changing curves, and even the textures of the wave face. When necessary, the inside rail tapers back to the tail, forming a natural, thin and flexible foil, with an absolute minimum of drag. Far closer to "jet-propelled bodysurfing" than bodyboarding, playing the intimate song of ever-changing balance between maximum speed and control, is much of what modern, high performance surfmat riding is all about."
This in response to a similar question asked on Sway's.
By the way, I am trying to collaborate on a Mat rider's gathering sometime this spring. Work is in progress to hash out a location and date. Interested parties please let me know or post at Surfmatz.