My club is having a contest where the goal is to fly a rocket 8 times in one day on each of the following twice: 1/2A6-2, A8-3, B6-4 and C6-5. If your rocket gets damaged, your DQ'd (not Dairy Queen). The other aspect of the contest, is the total cumulative flight time of all 8 flights (assuming your rocket is still alive). So you want it to go low and fall fast. So I was considering replacing normal fins with a disc. I have attached a OR screen shot to show what I mean (the best rendering I can do in OR). But the CP is much higher than I think it would be for real. Anyone have experience with this or something similar? For simulation purposes, the fins are 2.5" high, 3' thick, and root and tip chord of .25". Material is balsa.