Negative tail rocker
Sorry Viking, but it's Raquel Welch who floats my boat - it's her eyes you know! [ I once nearly sued her for aggravated injury when she invaded a dream and I almost fell out of bed in excitement.]
I do have a photo of that day [but don't know how to post it] just as the board reared up and crashed. It did earn me the the 'Flying Vinta' nickname - a couple of peeved Neil Pryde powered buddies hurled that one about! The point is, though, that it DEFINITELY was faster once the concaves deepened, and the tail sagged. It just became too difficult to handle. The impression was, of a flat stone skimming the surface of the water but still in contact, rather than the usual rearing up anf riding off the fin. The bent down tail seemed to hold the board down, so just what IS the fastest bottom shape for a board?