It started with a True Ames L flex regular base in hopes it would get some bite and projection out of the turns. It was easy to overpower the fin's flexible tip so the board would "chirp" back if it was pushed too hard. A "chirp" is when the fin suddenly grabs and projects whilst you're gettin' yer drift on. The fin was placed with the trailing edge of the base 12.5" inches from the tail. Sometimes whilst in trim, it was hard to disengage and drop down to get more speed to make a section. When it was pushed up and inch and a half, the board loosened up and worked top to bottom with ease. The past two sessions, it ran a 9" Gl Flex Volan fin from Fibre Glas Fin Co. (Larry Allison). First, with the fin's trailing edge at 12.5" from tail like the TA fin. Major improvement in smoothness during turns and adjustments. It still hung up in trim so fwd an inch and a half it cleaned up. Fin placement is so critical on these boards and each board and pilot are different. Start the fin in the middle and work it out these days.
Below is some footage of said board being ridden in some high tide waves at 1st point. The conditions were good but the backwash made for some interesting rides. Waves were shoulder/chest high.