Wow another one of thoses learning curve days,  Rig sail up perfecly, sand down fin to get flush, oh dear, sanded the bottom as did not know about sanding the ends, school boy error, sanded it and sanded it and sanded it and still not getting lower, put in tighten up and back bolt rips out fin insert, shit, so took a risk and had first two- three runs down wall, made me very nervous as fin now also had alot of side to side movement as only being held in with one bolt so could pull back part fin out, then on way back and still worring about fin got pulled into sail and put knee though second panel, well game over as no other small sails or small fins to used,  Dam it, this could, would have been my fastest ever day, lots of speed sailers here today so good to see everyone. as always, better luck neck time.