modern twin fin keel placement

So I finished shaping my board and placed the fin box (rastovich keel fins) at about 10" with 1/2" toed in and about 1" off the rail. I figured that the extra distance from the tail would have loosened up the board a bit but it is tracking… the board does have a lot of drive and I want to keep that, but also want it to be able to turn quickly. I have tried smaller keel fins but those are too loose and feel gutless. Otherwise the board is great and I want to remake it. It is more of a modern shortboard design with a single concave to double concave and vee out the back, hard rails in the back 12", nice and full throughout.  Where should place the fins on a board like this to keep the positive drive feel with the rastovich futures fins, without making the board track and keeping it nice and loose?

demensions: 6’2" x 19 1/8" x 2 7/16"

wide point about 1" up from center.  

tail rocker: 1 7/8" 

width at tail: 9 7/16

thickness at tail: 1 1/4

butcrack: about 3 1/2" deep

single concave to double concave with vee out the back. 

tartan2tartan1

thank you very much for the help and sorry for another twin fin placement question, but everything else on here was for fish boards with wide tails,  I didnt see anything related to a more modern outline / dimensions twin fin with keel fins. 

Thank you for the help, 

Todd

Hi Todd,

Looks to me like you have more of a swallowtail than a fish and perhaps keels are not the best choice for your board.  You might try a pair of twin fin fins to loosen it up, or a look at a quad setup. Mike

So what would be a good recommendation for a regular twin fin placement. Or why is this board tracking? is it the 1/2" toe?