Siren "747" SUP Fin

The Siren "747" SUP Fin was design specifically for open ocean SUPing where downwind prowess in the bump separates the winners from the loosers.  The key to downwind paddling in the bump is to keep the board in plane at all times while retaining the control required to make the quick directional changes that will take you from one bump to the next.  That's the reason for the 747's high aspect ratio.  The upright character of the fin allows the paddler to quickly navigate the chop by eliminating the tendency of a more raked fin to "track," or resist changes in direction.  In addition, the foil sections used to create the Siren "747" are thicker than the other fins in the line-up,  which adds to the fin's manuverability.  Because the bump gives us ample "horsepower," we can sacrifice the shear speed of a thinner fin for the agility of a thicker fin without worrying about the impact on the fin's efficiency.  The added rigidity of the extra thickness, when coupled with a Curtis Fin foil, has the added benefit of producing a fin that is also extremely efficient.  As a final touch, we added a radiused entry point to the base of the leading edge of the fin to help shed kelp and weeds.

In order to enhance directional stability, we have added chord length to the foil sections at the tip of the fin (hence the "cut away" effect) for directional stability.  This reduces the rider's need to reach and torque with the paddle to correct course, which results in wasted energy.  The Sirenby Curtis Fins 747 SUP fin is the perfect balance between directional stability, manuverability and efficiency.

The result of extensive R&D, the stand-alone speed and performance of a Siren by Curtis Fins SUP fin is a result of not only conscientious design work that relies upon proven hydrodynamic theory, but is also the result of sound composite engineering.  Designed using sophistocated CAD, CAM and solid modeling techniques, every foil section is carefully selected by Curtis to ensure optimum performance; relying upon feedback from the Curtis Fins team to drive each fin's evolution.

Anatomy of a Siren by Curtis Fins SUP fin:

A Siren SUP fins by Curtis Fins begins by pressure laminating thin sheets of fiberglass together in a hydraulic press.  This results in a fiberglass blank that consists of more continuous strands of glass than the traditional single-sheet wet-layup method of producing fin blanks -- which in turn equates to enhanced stiffness.  By producing blanks with a higher flexural modulous (i.e., high rigidity), we are able make the fin thinner, which enhances efficiency, and therefore speed, through the water.

The fin blank is then fixtured in a CNC machine for precise, reliable reproduction of Curtis' original design.  Subtleties make the difference when it comes to fin design, where small changes in foil shape can have a big impact on performance.  No other mode of reproduction can compare to the CNC's ability to consistently deliver the key design components that make a Siren by Curtis Fin not only a performer, but a work of art.

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