How to Mark Fin Placement on a Surfboard

When building a surfboard, it is essential to mark fin placement on the surfboard correctly. The fin plays an important role in the way the surfboard reacts to waves, and improper placement can reduce your surfing enjoyment by hampering the performance of the board.

Things You'll Need

  • Pencil
  • T-square
  • Measuring tape
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Instructions

    • 1

      Lay the board upside down on a flat surface. Draw a center line on the board from tip to tail. This is your "stringer line."

    • 2

      Use a T-square to draw a "cross line" four inches up from the tail. This is the marker for the back end of your fins.

    • 3

      Place the centerboard fin on the stringer line, with the back end lined up flush with your cross line. Be certain the fin is lined up evenly, and then make a small mark at the front of it on the stringer line. Remove the fin.

    • 4

      Measure 11 inches up the stringer line and draw another cross line.

    • 5

      Mark side fin placement the second cross line, six inches on either side of the stringer line. This marks the back of your side fins.

    • 6

      Line up the back of the side fins with each mark on the cross line. Get them to a perfect 90-degree angle.

    • 7

      Toe in each fin a half inch. Mark the front of the placement of the front of the fins and remove. You now have fin placement marks and are ready to permanently attach the fins.