I admit it, I’m not a fan of fancy curves on board bottoms. I think one of the biggest compromises in board design is making a bottom which will glide well and turn well too. A good compromise of these two aspects must also offer acceptable tail characteristics for paddling and drop/turning. Water dislikes moving slowly, but water hates moving rapidly. I think it’s no accident that we discovered tail V only after Rennie Yater invented progressive tail rocker. Wide flat sterns provide good lift for stroking into waves. Yater rocker provides good stability and glide. Tail V provides good turning characteristics. When trimming, a sharp transition from flat entry to tail V can slow a board down, as can sharp Yater tail rocker. I think a good compromise is to keep the transition from flat entry to tail V smooth and gentle. Then at the tail, where the stringer is really curving upward, the tail’s V’ed rail is curving smoothly back almost to a level stern. When paddling into a wave, this combination gives the tail rail lift where the rocker would be dragging. The stringer rocker forces water outward to the tail rails. The setup turns a negative into a positive. In this way you can minimize drag, and get tail V’s turning advantage without giving up tail lift. Whaddya think?
Noodle - yes, I understand what you’re saying and it makes perfect sense to me. I think that in addition to the vee, the curvature of the tail rocker plays a huge role in how a board rides. I’ve tried to explain this in terms of raw “tail rocker” measurements to people I’ve shaped boards for. Take a “3 inch tail rocker” for instance - start with a perfectly flat rocker and 12" from the tail connect a straight line to a point 3" above the flat and you have one type of “3 inch tail rocker.” Now with the same perfectly flat rocker, start 36" from the tail and with a straight line connect to a point 3" above the flat and you have a totally different “3 inch tail rocker.” Obviously, rocker doesn’t involve straight lines but I think you get the picture. I have personally ridden two different boards - one a flattened tail rocker (Skip Frye) and another progressive tail rocker (Jacobs) at the same break on the same day literally trading off back and forth several times for the sake of validation and there is no question in my mind that the flattened version offered more compression, drive and SPEED! In hollow waves a progressive tail rocker can prevent trouble sometimes and on longboards keep the tail sucked down for nose riding but overall, I’ll take the flattened version for everyday riding characteristics.