All things said are worth checking. However, Roger probably can't say much about the Drake fins. I received two with my 2008 iSonic 111 (a 38 and 44). Both would spin out all the time with little back foot pressure. I also sanded them with no success. I bought a Tectonics Tomcat 42 and presto - no spin out. I can and have pushed it hard enough to spin it out, but if I do, it comes back in line with ease. Not so with the Drakes.
Formula 160; iSonic 111; HiFly Move 105; Tiga 263; '85 Mistral Superlight.
Maui Sails TR 11.0; 9.2; 8.4; 7.6; 6.6; Maui Sails Switch 6.0; 5.2; Maui Sails Global 4.5; 4.0.