NOTE

• Fin screws for back fins should be placed on the stringer side of the fin! Check the fin-dots on the drawing above.
• Distance given can be varied according to tail width. Download the M5 formula to see which distance corresponds with each tail.
•  Careful when marking and drilling tail-fin position and plug holes! For guns use central fin location template on tail fins and central fin jig.
• With shortboards, using the side fin location template on rear fins means that the double foiled fins trailing edge will be 1/8″ towards the rail or total distance between fins 1/4″ more than specified in the formula. For ease of production use side template as the difference although apparent should only give more drive. If concerned, reduce 1/8″ from distance from happy medium.
• NOTE ON USE OF FCS: Fcs rail plugs are recomended for back fins on boards with concave tails. For Vee-bottoms, FCS central fin plugs are more appropriate. Check the angle of the upper face of the plug with the fin-jig in place at the correct 2.5 degree angle to see which plug best coincides with the angle of the bottom surface of your board.