well i saw mr burton, told him what i hoped to achieve and he did some measurements. took the board to polsie and here is the result
back fins 51/2 inch from the tail with a narrow throat and decided on sa large quad set.
i hurt my knee a week ago, but couldn't resist having a go. i had a few rides on my 8 10 and the knee is a bit unstable and had a few wobbles in the onshore waves.anyway, i went in and took the sb out.didn't gain much stability i was hoping for with the narrow throat, but it paddled better than the sunny setup. it's not easy to stay on at the best of times, so the onshore/rips was making it tough. i have to keep a good posture with shoulders set down and back or it's good night nurse.now the surfing part, my first impressions- a hell of a lot faster and looser than it was as two plus one or thruster. i was very pleased with the speed gain considering the rocker in the board. easily the closest to a shortboard i have been on
cheers